Ran Tian, , , Jiayang Li, , , Yu Xia, , , Juan Li*, , , Ligang Hu*, , and , Richard N. Zare*,
{"title":"3D-Printed Field-free Ionization Source for Mass Spectrometry","authors":"Ran Tian, , , Jiayang Li, , , Yu Xia, , , Juan Li*, , , Ligang Hu*, , and , Richard N. Zare*, ","doi":"10.1021/acs.analchem.5c05002","DOIUrl":"10.1021/acs.analchem.5c05002","url":null,"abstract":"<p >Most ambient ionization methods for mass spectrometry require externally applied high-voltage fields to generate charged droplets, limiting their portability and energy efficiency. We report a fully three-dimensional (3D)-printed ionization source, in which a standalone atomizer functions as the droplet-generating ionizer by enabling spontaneous charging through gas–solid triboelectric interactions. The device features a coaxial flow configuration, in which high-velocity sheath gas interacts with a BaTiO<sub>3</sub>-doped poly(lactic acid) (PLA) nozzle surface, generating interfacial charges that are transferred to emerging droplets. Computational fluid dynamics simulations confirm sustained wall shear stress near the outlet, supporting the proposed charge-generation mechanism. By tuning the nozzle’s dielectric composition and outlet geometry, droplet charge density and size can be precisely modulated up to 0.3 nC/μL under optimized conditions. Faraday cup measurements reveal a clear correlation between the structural parameters and total droplet charge. Using methyl viologen (MV<sup>2+</sup>) as a single-electron probe, mass spectra revealed efficient electron transfer and secondary product formation, confirming enhanced interfacial electron availability. These results demonstrate that triboelectric enhancement via a 3D-printed design enables voltage-free ion generation and controllable electron transfer, offering a structurally simple, low-cost, and power-free approach to ambient chemical analysis.</p>","PeriodicalId":27,"journal":{"name":"Analytical Chemistry","volume":"97 40","pages":"22390–22396"},"PeriodicalIF":6.7,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145229045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Core-Sheath Braided Yarn-Based Wearable Bioelectronics for Sweat Capture and Multimodal Sensing.","authors":"Shanshan Gong,Xuanqi Rao,Yun Li,Hanyu Guo,Changling Miao,Jingyao Song,Mengfan Zhang,Yiru Zhou,Xueping Zhang,You Yu","doi":"10.1021/acs.analchem.5c05260","DOIUrl":"https://doi.org/10.1021/acs.analchem.5c05260","url":null,"abstract":"Breathable and comfortable wearable biosensing textiles capable of detecting multiple biomarkers in human sweat offer a promising approach to continuous health monitoring in daily life. Current wearable flexible electrochemical textiles face limitations in multibiomarker integration and often require large surface areas and excessive sweat volumes to activate the sensors. Here, we report a highly integrated sweat sensor based on a multifunctional core-sheath sensor, which integrates multiple electrodes in a three-dimensional spatially isolated manner in a single yarn through an improved braiding process, drives the directional flow of sweat based on the synergistic action of wettability gradient and yarn structure to significantly shorten the transmission path, and enhances the mechanical strength and dynamic deformation stability of the sensor through a helix-crossing braiding structure. The combination of high sensitivity and comfort provides a new idea for the mass production of low-cost, multiparameter health monitoring devices.","PeriodicalId":27,"journal":{"name":"Analytical Chemistry","volume":"3 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145229235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Heat-Induced Protein Oxidation as an Impediment for Thermal Stability Measurements: A Case Study on Cytochrome c","authors":"Evelyn H. MacKay-Barr, Lars Konermann","doi":"10.1021/acs.analchem.5c04434","DOIUrl":"https://doi.org/10.1021/acs.analchem.5c04434","url":null,"abstract":"Thermal unfolding (“melting”) experiments are widely used for protein stability measurements. These assays probe spectroscopic properties of the protein while gradually increasing the solution temperature until unfolding is complete. Thermodynamic parameters are obtained from fits of the resulting profiles. Differential scanning calorimetry relies on similar concepts. Meaningful stability measurements require reversible conditions, where the protein fluctuates between its native and unfolded states (N ⇌ U), as governed by the temperature-dependent equilibrium constant. A simple reversibility test is to ensure that heating and cooling (unfolding and refolding) profiles are superimposable. Unfortunately, such tests are not commonly performed. Here, we focused on cytochrome <i>c</i>, one of the most widely used model proteins for folding studies. Surprisingly, thermal unfolding/refolding was found to be irreversible, even in the absence of aggregation. Using mass spectrometry (MS), we traced the origin of this irreversibility to oxidative side chain modifications that accumulate during thermal assays. By gradually altering the covalent composition of the protein, oxidation creates a scenario far from ideal N ⇌ U conditions, rendering the validity of fitted thermodynamic parameters questionable. Oxidation at Tyr, Trp, and Met residues was promoted by dissolved O<sub>2</sub>. It appears that the role of oxidation as an impediment for protein stability assays has been overlooked in the past. While the use of deoxygenated solutions represents a partial remedy, it is hoped that better oxidation suppression strategies will be developed in the future. In any case, it is advisable to perform MS measurements alongside thermal protein stability experiments to ensure that problems related to oxidation-mediated irreversibility are properly recognized.","PeriodicalId":27,"journal":{"name":"Analytical Chemistry","volume":"123 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145235019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Antibody-Free Inline Dual-Retention Nano-WCX-μSPE-MS/MS for Quantification of Intact Parathyroid Hormone and Antagonistic Fragments in Clinical Serum","authors":"Anping Wang, Jinlan Yang, Siqi Zhao, Yanyan Li, Li Yang, Xinhua Guo","doi":"10.1021/acs.analchem.5c03332","DOIUrl":"https://doi.org/10.1021/acs.analchem.5c03332","url":null,"abstract":"Parathyroid hormone (PTH), an 84-amino acid polypeptide critical for calcium/phosphorus homeostasis, exhibits significant analytical challenges in clinical quantification, particularly in chronic kidney disease (CKD) patients due to its low circulating concentrations, biological matrix complexity, and interference from circulating PTH fragments. Traditional immunoassays may either overestimate the PTH level due to cross-reactivity with the PTH 7–84 or fail to quantify the antagonistic fragment. Highly sensitive and selective mass spectrometry (MS)-based methods could be used as the reference measurement procedure (RMP) for PTH assays, once the limitations of quantification thresholds and antibody-dependent workflows are addressed. Here, we introduce the first inline weak cation-exchange microsolid-phase extraction-tandem mass spectrometry (WCX-μSPE-MS/MS) method for simultaneous quantification of PTH 1–84 and its antagonist PTH 7–84 in clinical serum samples. A carboxyl-functionalized polystyrene nanosphere-modified capillary μSPE column with dual weak cation exchange (WCX) and nonpolar retention mechanisms is integrated with electrospray ionization-MS/MS, enabling online purification, enrichment, and detection in a single analysis. The nanoliter-scale capillary extraction can minimize matrix effects and improve sensitivity while greatly eliminating offline sample transfer steps. A limit of detection (LOD) as low as 6.0 pg/mL (PTH 1–84) or 9.0 pg/mL (PTH 7–84) is achieved, with relative standard deviations less than 10%. Our antibody-free strategy greatly reduces solvent/sample consumption, avoids manual errors, and has been successfully applied for accurate quantification of both PTH 1–84 and PTH 7–84 in clinical serum, demonstrating great potential to serve as an RMP for PTH assays, enhancing diagnostic accuracy for hyperparathyroidism, CKD, and renal bone diseases.","PeriodicalId":27,"journal":{"name":"Analytical Chemistry","volume":"18 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145235017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yifan Ma, Kai Wang, Hanyu Li, Xilin Wang, Rong-Mei Kong, Yan Zhao, Weiheng Kong, Fengli Qu
{"title":"From Serum to Organ: The Amine-Naphthalene Modular Platform Enables Precise Identification and Quantification of Alkaline Phosphatase","authors":"Yifan Ma, Kai Wang, Hanyu Li, Xilin Wang, Rong-Mei Kong, Yan Zhao, Weiheng Kong, Fengli Qu","doi":"10.1021/acs.analchem.5c05007","DOIUrl":"https://doi.org/10.1021/acs.analchem.5c05007","url":null,"abstract":"Accurate detection of alkaline phosphatase (ALP) is critical for clinical diagnosis and mechanistic studies across diverse tissues. Here, we present a modular “off-on” fluorescent probe platform based on 1-naphthol phosphate sodium (1-NPP) and ethylenediamine (EDA), enabling precise, rapid, and cost-effective quantification of ALP activity from serum to whole organs. The probe’s mechanism relies on the ALP-catalyzed hydrolysis of 1-NPP to liberate 1-naphthol, which subsequently reacts with EDA to generate a robust fluorescent signal. This system demonstrates high sensitivity, with a detection limit of 0.068 mU/mL, and maintains excellent linearity and stability across complex biological matrices including serum, cell lysates, and tissue homogenates. Application in various cell lines and mice organs revealed organ- and disease-specific ALP activity distributions, highlighting its utility for distinguishing physiological and pathological states. The probe’s low cytotoxicity and straightforward preparation offer significant advantages over nanoparticle-based sensors. Overall, this work establishes a versatile and scalable platform for ALP analysis, whose remarkable ability to distinguish ALP activity across cells and organs underpins its broad potential for early disease surveillance, mechanistic exploration, and high-throughput screening.","PeriodicalId":27,"journal":{"name":"Analytical Chemistry","volume":"108 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145235021","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Integrated Multimodal Enhanced Raman Spectroscopy (iMERS) Enables Live Single-Cell Multimolecular Profiling","authors":"Shengjie Chen, , , Kunru Yu, , and , Rong Zhu*, ","doi":"10.1021/acs.analchem.5c03235","DOIUrl":"10.1021/acs.analchem.5c03235","url":null,"abstract":"<p >Single-cell multimolecular profiling provides a holistic understanding of cellular heterogeneity and metabolic mechanisms. A label-free spectroscopic approach is expected to advance multimolecular analysis, particularly for the interpretation of small-molecule metabolomics, but faces a great challenge in terms of poor sensitivity. Here, we propose an integrated multimodal enhanced Raman spectroscopy (iMERS) method for the semiquantitative molecular profiling of intracellular and extracellular molecules of single cells. The iMERS method involves a cost-effective and well-controllable nanofabrication for surface-enhanced Raman scattering (SERS), an adaptive spectral signal recovery and a quantitative regression algorithm based on digitized Raman signature, and a proactive stimulation-assisted single-cell profiling. Through the iMERS approach, cellular multimolecular information can be quantitatively acquired from the label-free spectra with high accuracy, high time efficiency, and cost-efficiency. We apply iMERS to recognize indistinguishable liver cancer subtypes, achieving an accuracy of up to 81%. The iMERS approach has promising potential for broad applications in single-cell multimolecular analysis, precision clinical medicine, etc.</p>","PeriodicalId":27,"journal":{"name":"Analytical Chemistry","volume":"97 40","pages":"21977–21985"},"PeriodicalIF":6.7,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145229043","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Low-Temperature Decarboxylation and Sensitive Detection of Trifluoroacetic Acid on the Interface of Active Amino Nickel Metal Organic Layers","authors":"Shuguang Yan, , , Hongjie Song, , , Zili Huang, , , Wenchang Wang, , , Yingying Su*, , and , Yi Lv*, ","doi":"10.1021/acs.analchem.5c05284","DOIUrl":"10.1021/acs.analchem.5c05284","url":null,"abstract":"<p >Trifluoroacetic acid (TFA), a common end degradation product of perfluorinated compounds (PFCs), presents a grave hazard to human health. Consequently, there is an imperative to construct novel methods of TFA degradation and sensing. Here, a TFA-amino-nickel metal–organic layer (NH<sub>2</sub>–Ni-MOLs) gas–solid interface reaction system was established. The gas–solid interface reaction was investigated in detail using X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (TOF-SIMS), theoretical calculations and XPS depth profiling. It was demonstrated that TFA anchored to the surface of NH<sub>2</sub>–Ni-MOLs at 40 °C by interactions of ligand with Ni<sup>2+</sup>. And then, the small molecules of fluoride produced by the continuous decarboxylation reaction of TFA adsorbed by NH<sub>2</sub>–Ni-MOLs, which ultimately formed the fluorine-containing small molecule nanointerface layer ultimately. Notably, the XPS integral area gradually increases with the concentration of fluorinated small molecules in the interfacial layer, and a novel strategy for the sensitive detection of TFA was developed. In summary, based on the NH<sub>2</sub>–Ni-MOLs-TFA gas–solid interface, efficient decarboxylation reaction of TFA at low temperature and the sensitive detection of TFA by XPS were achieved, which will open a unique avenue for the degradation and sensitive detection of PFCs.</p>","PeriodicalId":27,"journal":{"name":"Analytical Chemistry","volume":"97 40","pages":"22436–22444"},"PeriodicalIF":6.7,"publicationDate":"2025-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145229083","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Broad-Spectrum Aptamer Selection of Challenging Retronecine-Type Hepatotoxic Pyrrolizidine Alkaloids for Biosensor Construction","authors":"Linhui Xie, , , Peiyao Chen, , , Dan Feng, , , Ting Gong, , , Jingyan Zhang, , , Tongtong Lai, , , Jiancai Tang, , , Shengmao Li*, , and , Yingping Luo*, ","doi":"10.1021/acs.analchem.5c01995","DOIUrl":"10.1021/acs.analchem.5c01995","url":null,"abstract":"<p >Since hepatotoxic pyrrolizidine alkaloids (HPAs) are a group of phytotoxins widely distributed all over the world, it is important to develop a fast and economical detection method to monitor HPA levels. Given that the aptamers are powerful recognition elements for sensing platform construction, herein we have isolated four HPA-binding aptamers for the first time using the library-immobilized systematic evolution of ligands by the exponential enrichment (SELEX) strategy. All of the selected aptamers could recognize retronecine-type HPAs and had excellent selectivity over other interferents. Two of the obtained aptamers were used to develop a strand-displacement fluorescent sensing platform that successfully detected 10 HPA chemicals in honey and tea samples, demonstrating the great potential of the selected aptamers in the application of safety evaluation in food, agriculture, medicine, and other fields. This work also provides new ideas for broad-spectrum aptamer selection for other challenging targets (with few functional groups and hydrophobic properties) using natural nucleic acid libraries.</p>","PeriodicalId":27,"journal":{"name":"Analytical Chemistry","volume":"97 40","pages":"21835–21842"},"PeriodicalIF":6.7,"publicationDate":"2025-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145229048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Monitoring Chemotherapeutic Drugs Release from the Single Core–Shell Nanocarrier at a Monolayer Graphene-Based Total Internal Reflection Imaging Platform","authors":"Jialu Chen, , , Zhimei He, , , Yapeng Li, , , Mengwei Chen, , , Zheng Cai, , , Yun Chen*, , , Yimin Fang*, , and , Hao Zhu*, ","doi":"10.1021/acs.analchem.5c04386","DOIUrl":"10.1021/acs.analchem.5c04386","url":null,"abstract":"<p >Core–shell nanostructures have emerged as promising nanocarriers for diverse biomedical applications including thermal therapy, drug delivery, and tissue engineering. When core–shell nanocarriers are used in combination with chemotherapeutic drugs to achieve a synergistic effect, it is essential to monitor the release of chemotherapeutic drugs at the single nanoparticle level because of its inherent heterogeneity, which is also constructive for the rational design of relevant nanomedicine. Here, we developed a monolayer graphene-based total internal reflection imaging platform to study the release of chemotherapeutic drugs from the individual gold coated silica core–shell (SiO<sub>2</sub>@Au CS) nanoparticles by detecting their surface charges in real-time. The nanoparticles oscillate under an alternating electric field, and the oscillation signal was extracted from the intense background with a Fourier transform filter, enabling precise determination of the surface charges of the individual nanoparticles. The combination of monolayer graphene and an evanescent field ensures high sensitivity while suppressing the noise level of the method, which contributes to a superiorly low detection limit. With the present setup, the loading and release behavior of doxorubicin on the individual SiO<sub>2</sub>@Au CS nanoparticles were monitored, and the corresponding kinetic constants were extracted. In addition, the release rate of doxorubicin from the nanocomposites induced by the thermal effects were examined at the single nanoparticle level. This work offers a promising tool to study the heterogeneity of the nanocarriers’ surface charges to further reveal their structure–activity relationships, which will also provide guidance for the study of the mechanism of their effects <i>in vivo</i>.</p>","PeriodicalId":27,"journal":{"name":"Analytical Chemistry","volume":"97 40","pages":"22250–22258"},"PeriodicalIF":6.7,"publicationDate":"2025-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145229081","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Highly Sensitive Detection of Estradiol Using Glass Micropipette Constructed via Polydopamine Nanotubes Filling and Small Molecule-Induced DNA Strand Dissociation","authors":"Jiacheng Dong, , , Yu Zhang, , , Zhongyu Yang, , , Yanhua Rao, , , Yueyue Feng, , , Liying Huang, , , Shiwei Xu, , , Guofeng Wang, , and , Nannan Liu*, ","doi":"10.1021/acs.analchem.5c04922","DOIUrl":"10.1021/acs.analchem.5c04922","url":null,"abstract":"<p >Endocrine-disrupting chemicals, particularly estradiol (E2), pose significant risks to environmental and human health due to their persistence and bioactivity. In this study, we developed a highly sensitive and label-free electrochemical sensor for E2 detection, based on a glass micropipette (GMP) filled with polydopamine nanotubes (PDA-NTs) and coupled with a small molecule-induced DNA strand dissociation strategy. PDA-NTs self-assemble into a densely packed structure at the tip of the GMP, providing abundant binding sites for E2 aptamer (Apt) immobilization and achieving the first signal amplification, which yields a detection limit of 1.29 pM. To further enhance sensitivity, a partially complementary DNA (cDNA) strand was hybridized with the aptamer to form an Apt-cDNA duplex. Upon E2 binding, the Apt in the Apt-cDNA duplex undergoes a conformational change that releases the sterically large cDNA, resulting in a significant increase in ionic current and enabling the second signal amplification. This second amplification improves the detection limit by 112-fold, reaching as low as 11.5 fM. The sensor can detect E2 in the detection range of 10 fM–10 nM and demonstrates high selectivity in complex mixed solutions such as fetal bovine serum (FBS) and environmental water. Beyond highly sensitive detection of E2, this dual-signal amplification also allows the detection of other small molecules through aptamer sequence replacement.</p>","PeriodicalId":27,"journal":{"name":"Analytical Chemistry","volume":"97 40","pages":"22418–22426"},"PeriodicalIF":6.7,"publicationDate":"2025-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145229087","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}