{"title":"Achiral Plasmonic Antennas Enhance Differential Absorption To Increase Preferential Detection of Chiral Single Molecules","authors":"Saaj Chattopadhyay, Julie S. Biteen","doi":"10.1021/acsmeasuresciau.4c00026","DOIUrl":null,"url":null,"abstract":"Plasmonic antennas increase the photon flux in their vicinity, which can lead to plasmon-enhanced fluorescence for molecules near these nanostructures. Here, we combine plasmon-coupled fluorescence and fluorescence-detected circular dichroism to build a specific and sensitive detection strategy for chiral single molecules. Electromagnetic simulations indicate that a two-dimensional gold nanoparticle dimer antenna enhances the electric field and optical chirality of a plane wave in its near field. Furthermore, this optical chirality enhancement can be tuned based on the polarization of the incident electric field, such that enhancing the optical chirality via these antennas will increase the differential absorption of parity-inverted fields. We measured the fluorescence from single molecules of chiral absorbers─Cy5 J-dimers assembled in double-stranded DNA backbones─and achieved increased detectability of these right-handed molecules near achiral gold nanoparticle dimer antennas under right circularly polarized illumination. This strategy offers a new approach to distinguishing weakly fluorescent enantiomers.","PeriodicalId":29800,"journal":{"name":"ACS Measurement Science Au","volume":null,"pages":null},"PeriodicalIF":4.6000,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"ACS Measurement Science Au","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1021/acsmeasuresciau.4c00026","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, ANALYTICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Plasmonic antennas increase the photon flux in their vicinity, which can lead to plasmon-enhanced fluorescence for molecules near these nanostructures. Here, we combine plasmon-coupled fluorescence and fluorescence-detected circular dichroism to build a specific and sensitive detection strategy for chiral single molecules. Electromagnetic simulations indicate that a two-dimensional gold nanoparticle dimer antenna enhances the electric field and optical chirality of a plane wave in its near field. Furthermore, this optical chirality enhancement can be tuned based on the polarization of the incident electric field, such that enhancing the optical chirality via these antennas will increase the differential absorption of parity-inverted fields. We measured the fluorescence from single molecules of chiral absorbers─Cy5 J-dimers assembled in double-stranded DNA backbones─and achieved increased detectability of these right-handed molecules near achiral gold nanoparticle dimer antennas under right circularly polarized illumination. This strategy offers a new approach to distinguishing weakly fluorescent enantiomers.
等离子体天线会增加其附近的光子通量,从而导致这些纳米结构附近的分子产生等离子体增强荧光。在这里,我们将等离子体耦合荧光和荧光检测圆二色性结合起来,建立了一种特异而灵敏的手性单分子检测策略。电磁模拟表明,二维金纳米粒子二聚体天线能增强近场平面波的电场和光学手性。此外,这种光学手性增强可根据入射电场的极化情况进行调整,因此通过这些天线增强光学手性将增加对奇偶反向场的差分吸收。我们测量了装配在双链 DNA 骨架中的手性吸收体--Cy5 J-二聚体--的单分子荧光,结果表明,在右旋圆极化照明下,这些右旋分子在非手性金纳米粒子二聚体天线附近的可探测性得到了提高。这种策略为区分弱荧光对映体提供了一种新方法。
期刊介绍:
ACS Measurement Science Au is an open access journal that publishes experimental computational or theoretical research in all areas of chemical measurement science. Short letters comprehensive articles reviews and perspectives are welcome on topics that report on any phase of analytical operations including sampling measurement and data analysis. This includes:Chemical Reactions and SelectivityChemometrics and Data ProcessingElectrochemistryElemental and Molecular CharacterizationImagingInstrumentationMass SpectrometryMicroscale and Nanoscale systemsOmics (Genomics Proteomics Metabonomics Metabolomics and Bioinformatics)Sensors and Sensing (Biosensors Chemical Sensors Gas Sensors Intracellular Sensors Single-Molecule Sensors Cell Chips Arrays Microfluidic Devices)SeparationsSpectroscopySurface analysisPapers dealing with established methods need to offer a significantly improved original application of the method.