{"title":"Surface enhanced Raman scattering microtips for microenvironment pH determination of semi-solid preparations.","authors":"Xiangxin Lu, Yunqing Wang, Rongchao Mei, Xiaomeng Chong, Lingxin Chen, Baoming Ning, Rongqin Zhang, Xuming Zhuang","doi":"10.1039/d4ay01523a","DOIUrl":"https://doi.org/10.1039/d4ay01523a","url":null,"abstract":"<p><p>Semi-solid preparations such as ointments, creams, gels, and pastes are common topical dosage forms with complex compositions and microstructures. pH is a critical quality attribute for semi-solid preparations, affecting properties such as particle size distribution, drug dissociation state, and rheological behavior. Currently, traditional pH electrode methods only provide an \"average\" pH for large-volume matrices, with low spatial resolution and accuracy. Microenvironment pH detection is crucial for accurately assessing semi-solid preparations. Herein, we developed pH-sensitive surface enhanced Raman scattering (SERS) microtips to achieve localized pH detection in semi-solid preparations. SERS microtips were prepared from glass needles with a tip size of around 1 μm and gold nanoparticles (Au NPs) grown <i>in situ</i> on glass surfaces for SERS enhancement. 4-Mercaptopyridine was selected as a pH sensitive Raman reporter and immobilized on the Au NPs, exhibiting characteristic Raman peak shifts within the pH range of 3-10. The SERS microtips were employed to conduct highly sensitive pH measurements in localized areas of 15 commercial ointments, 8 gels, and 1 laboratory-made ointment, providing higher spatial resolution and microenvironment differentiation compared to pH meters. The SERS microtips were used to monitor pH changes over time in ointment applied to localized wounds on live mice. This work introduces a new tool for pH detection in semi-solid preparations, offering a new method to enhance the prescription process and quality assessment of complex preparations like topical semi-solid preparations.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142379517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A label-free and ultrasensitive electrochemical biosensor using hybrid polypyrrole/gold nanoelectrocatalyst mediated signal amplification for the detection of miRNA-21.","authors":"LiNa Zhang, YanBin He","doi":"10.1039/d4ay01215a","DOIUrl":"https://doi.org/10.1039/d4ay01215a","url":null,"abstract":"<p><p>The quantitative detection of microRNAs (miRNAs) is crucial for the diagnosis of cancers, while the traditional methods involve complicated procedures and restricted signal gain. In this study, we have established an ultrasensitive electrochemical biosensor by combining a target-induced hybridization reaction and signal amplification strategy for the detection of miRNA-21. The signal amplification is achieved through employing double-stranded DNA as scaffolds for methylene blue (MB) and using a polypyrrole@gold nanocomposite (ppy@AuNPs) as the electrochemical catalyst for further enhancing the signal. Therefore, this proposed electrochemical platform displayed an analytical performance with a wide linear range from 10 fM to 100 nM and a low detection limit down to 5.4 fM. The excellent selectivity allows the biosensor to discriminate miRNA-21 from other miRNAs, even the one base-mismatched sequence. Moreover, this nanoelectrocatalyst-based platform exhibited good reproducibility and remarkable storage stability, which shows great potential for miRNA-21 detection.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142379511","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shan Liu, Yuemeng Chen, Fang Wang, Song Bai, JingJie Wu
{"title":"Analysis of synthetic route and case correlation of methamphetamine crystals seized by ultra-high-performance liquid chromatography-mass spectrometry (UPLC-MS/MS) and Pearson correlation coefficient method.","authors":"Shan Liu, Yuemeng Chen, Fang Wang, Song Bai, JingJie Wu","doi":"10.1039/d4ay01519c","DOIUrl":"https://doi.org/10.1039/d4ay01519c","url":null,"abstract":"<p><p>Analysis of impurities in illicit drugs provides key information on the manufacture and distribution of methamphetamine (MA). An analysis of 22 specific target compounds in unlawful MA products was conducted using ultra-high-performance liquid chromatography-mass spectrometry (UPLC-MS/MS). The peak area of the alkaloids was utilized as an important calculation data variable to determine the synthesis method. The results demonstrated that the application of target screening techniques for trace impurity components in samples can aid in determining the synthesis process routes for toxin production in 169 samples. These samples were initially categorized based on their synthesis modes, specifically synthesis routes <i>N</i>, <i>E</i>, and <i>R</i>. The correlation analysis of MA samples with known synthetic routes was carried out using principal coordinate analysis (PCoA) and the Pearson correlation coefficient method. Among the <i>N</i> and <i>R</i> synthesis routes, 15 and 7 groups with strong correlation were screened, respectively. Consistent with the observed scenario, the samples from the synthetic route <i>E</i> showed limited correlation with each other. The experiment provides a focused framework for the management of synthetic raw materials used for the production of drugs and the investigation of drug-related cases. This facilitates a holistic strategy to combat drug-related crimes, from manufacturing laboratory to end-user.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142379513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Quantification of creatinine in whole blood by a paper-based device using an RGB sensor.","authors":"Neha Gautam, Ranjana Verma, Priya Ranjan Muduli, Shantimoy Kar, Arnab Sarkar","doi":"10.1039/d4ay01476f","DOIUrl":"https://doi.org/10.1039/d4ay01476f","url":null,"abstract":"<p><p>Creatinine, an important biomarker for renal functions, is often conventionally estimated using the gold standard Jaffe reaction from blood, which involves the usage of a spectrophotometric measurement, thus restricting its utilization scope in point-of-care settings. Here, we report the development of a method for the single-step quantification of creatinine from whole blood using a paper-based microfluidic device. Our platform uses Whatman filter paper integrated with an LF1 membrane. The on-chip separation of blood plasma is achieved through the LF1 membrane, while the Whatman component of the device contains the embedded reagents for the Jaffe reaction. The combination of two different grades of paper enables a single-step quantification of creatinine as the separated blood plasma traverses to the reaction zone through capillary imbibition. Colorimetric readouts were quantified using an RGB sensor instead of a smartphone, which is highly platform dependent and incurs a relatively higher cost compared to the other components in typical point-of care (POC) devices. Our sensor was integrated within a 3D box, thereby making the detection virtually instrument free and perfectly suited for POC settings. The limit of detection (LOD) of our device was 0.219 mg dL<sup>-1</sup>, which falls within the lower range of physiological values. The coefficient of determination (<i>R</i><sup>2</sup>) for the linearity and median accuracy were 0.978 and 94.047%, respectively. The relative standard deviation (RSD) for precision measurements remained below 5% for the developed protocol. Furthermore, we validated the performance of our device with 35 clinical samples in laboratory settings against the gold standard measurements. Our Bland-Altman plot as well as <i>t</i>-test and chi-square test results clearly confirmed the validity of our device within a 95% confidence interval.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142379515","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Junyu Zhang, Yi Chen, Yiyang He, Yiwen Bai, Wei Wang, Guangxin Yang, Cong Kong, Xiao Cao, Lin Gu
{"title":"Fruit waste-derived carbon dots with rhodamine B for the ratiometric detection of Fe<sup>3+</sup> and Cu<sup>2</sup>.","authors":"Junyu Zhang, Yi Chen, Yiyang He, Yiwen Bai, Wei Wang, Guangxin Yang, Cong Kong, Xiao Cao, Lin Gu","doi":"10.1039/d4ay01539h","DOIUrl":"https://doi.org/10.1039/d4ay01539h","url":null,"abstract":"<p><p>A green and eco-friendly solvothermal approach is proposed for the synthesis of carbon quantum dots (CQDs) from watermelon rind. The as-prepared CQDs exhibited superior teal fluorescence in aqueous solutions, with a quantum yield of 13.9%. The CQDs and rhodamine B (RhB) were demonstrated to selectively react with Fe<sup>3+</sup> and Cu<sup>2+</sup>, leading to a fluorescence (FL) quenching effect, which was successfully used for constructing \"double-response-off\" type ratiometric FL probes. A comparative study was conducted to assess the sensitivity and accuracy of ratiometric fluorescent probes, specifically those based on CQDs alone and in combination with RhB, for the selective detection of Fe<sup>3+</sup> and Cu<sup>2+</sup>. By plotting the ratio of the differential fluorescence (Δ<i>F</i>) signals of CQDs to that of RhB against the practical application analyte concentration, the detection limits for Fe<sup>3+</sup> (1.75 μM) and Cu<sup>2+</sup> (0.43 μM) were markedly improved. The quenching mechanism was further explored, and the detection of Fe<sup>3+</sup> and Cu<sup>2+</sup> in surface water was demonstrated, showcasing the potential of efficient and effective nanosensors based on a static quenching effect. Futhermore, the addition of ascorbic acid can restore the fluorescence quenched by Fe<sup>3+</sup>. Therefore, in the presence of copper and iron, the ratiometric probe can demonstrate the ability to identify two different metals.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142370266","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Taohong Zhou, Jin Lin, Fengmei Jin, Yanxing Yao, Zhihao Li, Lihua Wang
{"title":"Rational design of monodispersed Au@Pt core-shell nanostructures with excellent peroxidase-mimicking activity for colorimetric detection of Cr(VI).","authors":"Taohong Zhou, Jin Lin, Fengmei Jin, Yanxing Yao, Zhihao Li, Lihua Wang","doi":"10.1039/d4ay01334d","DOIUrl":"https://doi.org/10.1039/d4ay01334d","url":null,"abstract":"<p><p>Cr(VI) is one of the most typical heavy metal contaminants and rapid detection of Cr(VI) is highly important in food control and public health. Herein, a core-shell Au@Pt nanozyme-based colorimetric assay was developed for the rapid and sensitive detection of Cr(VI). The monodispersed Au@Pt core-shell nanoparticles exhibited high peroxidase-mimicking activity and can catalyze colorless TMB into blue-colored oxidized oxTMB. After the addition of Cr(VI), the oxTMB molecules can be reduced into colorless TMB. The ultrathin Pt shell can prevent the Pt component from aggregation, thus improving the catalytic activity of Au@Pt nanozyme. These Au@Pt nanozyme-based Cr(VI) assays exhibited high sensitivity and selectivity and displayed satisfactory recoveries in practical samples. Our work highlights opportunities for the development of core-shell nanozymes with extensive applications in food safety, biomedicine, and environmental monitoring.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142370267","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A porphyrin-modified CoMoO<sub>4</sub> nanosensor array for the detection of crude baijiu.","authors":"Peng Zhao, Xuhui Xia, Yiyao Luo, Zirui Yuan, Jiaxi Deng, Huibo Luo, Xiaogang Luo, Danqun Huo, Changjun Hou","doi":"10.1039/d4ay01082e","DOIUrl":"https://doi.org/10.1039/d4ay01082e","url":null,"abstract":"<p><p>The rapid classification of crude baijiu is pivotal for its industrialization and automated development. In this study, a colorimetric sensor array employing peroxidase nanase (Por-CoMoO<sub>4</sub>) was developed to detect reducing substances and crude baijiu. The peroxidase-like activity of CoMoO<sub>4</sub> was significantly enhanced by porphyrin (Por), exhibiting a <i>K</i><sub>m</sub> value of 0.044 mM and <i>V</i><sub>max</sub> of 19.37 × 10<sup>-8</sup> for TMB substrate. Peroxidase activity varies at different pH levels. Organic and crude baijiu scavenge free radicals, thereby inhibiting oxTMB formation and yielding distinctive fingerprint profiles. Using linear discriminant analysis, 14 types of small molecules and 16 varieties of Luzhou-flavor crude baijiu were identified within specific concentration ranges. The method achieved 100% accuracy in distinguishing baijiu samples sourced from different distilleries, offering a straightforward, rapid, and effective approach to differentiate crude baijiu during alcoholic beverage production.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142370263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Guo-Ying Chen, Mao-Ling Luo, Li Chen, Jia-Li Wang, Tong-Qing Chai, Dan Wang, Feng-Qing Yang
{"title":"Correction: Selective fluorescence detection of acetylsalicylic acid, succinic acid and ascorbic acid based on a responsive lanthanide metal fluorescent coordination polymer.","authors":"Guo-Ying Chen, Mao-Ling Luo, Li Chen, Jia-Li Wang, Tong-Qing Chai, Dan Wang, Feng-Qing Yang","doi":"10.1039/d4ay90110j","DOIUrl":"https://doi.org/10.1039/d4ay90110j","url":null,"abstract":"<p><p>Correction for 'Selective fluorescence detection of acetylsalicylic acid, succinic acid and ascorbic acid based on a responsive lanthanide metal fluorescent coordination polymer' by Guo-Ying Chen <i>et al.</i>, <i>Anal. Methods</i>, 2024, <b>16</b>, 4981-4994, https://doi.org/10.1039/d4ay00696h.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142370265","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hang Gong, Shufen Yao, Yong Li, Chunyan Chen, Feng Chen, Changqun Cai
{"title":"Combined detection of hepatitis B virus surface antigen and hepatitis B virus DNA using a DNA sensor.","authors":"Hang Gong, Shufen Yao, Yong Li, Chunyan Chen, Feng Chen, Changqun Cai","doi":"10.1039/d4ay01629g","DOIUrl":"https://doi.org/10.1039/d4ay01629g","url":null,"abstract":"<p><p>Hepatitis B virus (HBV) infection is associated with the progression of liver disease. Occult HBV infection (OBI) is defined as the existence of detectable HBV DNA in HBV surface antigen negative individuals. However, HBV DNA is negative in serum while HBV surface antigen remains positive in incompletely cured chronic HBV infection. Hence, combined detection of HBV surface antigen and HBV DNA is essential for the accurate detection and rehabilitation of HBV infection. Therefore, a multiplex detection strategy based on branched DNA nanostructures was developed. The single-stranded segment of a branched DNA nanostructure (segments of S4 and S2) assembled by four single-stranded DNA was hybridized with the aptamer of HBV surface antigen and DNA hairpin to construct a DNA nanosensor, which can achieve high specificity identification and highly sensitive fluorescence responses to the targets. The detection limits of the developed nanosensor for HBV and HBV DNA are 50 pM and 5 nM, respectively. The combined detection of HBV surface antigen and HBV DNA provides a new insight for more thorough diagnostic evaluation of HBV infection and rehabilitation.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142370264","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Douglas P M Saraiva, Bruno Ferreira, Leonardo M A Ribeiro, Thiago R L C Paixão, Mauro Bertotti
{"title":"Cost-effective quantification of uric acid using niobium oxide and graphene oxide-modified pencil-drawn electrodes on PVC substrates.","authors":"Douglas P M Saraiva, Bruno Ferreira, Leonardo M A Ribeiro, Thiago R L C Paixão, Mauro Bertotti","doi":"10.1039/d4ay01345j","DOIUrl":"10.1039/d4ay01345j","url":null,"abstract":"<p><p>This study introduces a cost-effective approach for quantifying uric acid (UA), the main antioxidant species in human physiology and implicated in inflammatory regulation. Using a PVC substrate and pencil drawing technique, electrodes were fabricated and modified with niobium oxide and graphene oxide <i>via</i> a straightforward \"drop casting\" method. The nanostructures of the substrate, electrode, and modified electrode were evaluated using SEM images. The synergistic effect between these materials significantly facilitated the uric acid oxidation process with a 400 mV peak potential shift and 45% current increase. The evaluation of the electrode's response to common blood and urine components showed minimal deviation. Among the components tested-ascorbic acid, glucose, nitrate, nitrite, cysteine, urea, creatinine, and ammonium ion-only the ammonium ion exhibited a 10% interference at concentrations commonly found in urine. The sensors showed a good detection limit of 8.7 μmol L<sup>-1</sup>, with a wide linear range from 8.7 to 2000 μmol L<sup>-1</sup> with a correlation factor of 0.9993 for five different sensors. The reproducibility and repeatability of the produced sensors were estimated by the RSD at 4% and 1%, respectively. Synthetic urine samples spiked exhibited reliable analysis, with recovery values within a 5% error margin. This work presents a practical, simple, and affordable sensor platform for rapid and accurate UA quantification.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142363518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}