TY - JOUR
T1 - Plasmonically-enhanced competitive assay for ultrasensitive and multiplexed detection of small molecules
AU - Wang, Zheyu
AU - Zhou, Qingjun
AU - Seth, Anushree
AU - Kolla, Samhitha
AU - Luan, Jingyi
AU - Jiang, Qisheng
AU - Rathi, Priya
AU - Gupta, Prashant
AU - Morrissey, Jeremiah J.
AU - Naik, Rajesh R.
AU - Singamaneni, Srikanth
N1 - Publisher Copyright:
© 2021 Elsevier B.V.
PY - 2022/3/15
Y1 - 2022/3/15
N2 - Novel methods that enable facile, ultrasensitive and multiplexed detection of low molecular weight organic compounds such as metabolites, drugs, additives, and organic pollutants are valuable in biomedical research, clinical diagnosis, food safety and environmental monitoring. Here, we demonstrate a simple, rapid, and ultrasensitive method for detection and quantification of small molecules by implementing a competitive immunoassay with an ultrabright fluorescent nanolabel, plasmonic fluor. Plasmonic-fluor is comprised of a polymer-coated gold nanorod and bovine serum albumin conjugated with molecular fluorophores and biotin. The synthesis steps and fluorescence emission of plasmonic-fluor was characterized by UV–vis spectroscopy, transmission electron microscopy, and fluorescence microscopy. Plasmon-enhanced competitive assay can be completed within 20 min and exhibited more than 30-fold lower limit-of-detection for cortisol compared to conventional competitive ELISA. The plasmon-enhanced competitive immunoassay when implemented as partition-free digital assay enabled further improvement in sensitivity. Further, spatially multiplexed plasmon-enhanced competitive assay enabled the simultaneous detection of two analytes (cortisol and fluorescein). This simple, rapid, and ultrasensitive method can be broadly employed for multiplexed detection of various small molecules in research, in-field and clinical settings.
AB - Novel methods that enable facile, ultrasensitive and multiplexed detection of low molecular weight organic compounds such as metabolites, drugs, additives, and organic pollutants are valuable in biomedical research, clinical diagnosis, food safety and environmental monitoring. Here, we demonstrate a simple, rapid, and ultrasensitive method for detection and quantification of small molecules by implementing a competitive immunoassay with an ultrabright fluorescent nanolabel, plasmonic fluor. Plasmonic-fluor is comprised of a polymer-coated gold nanorod and bovine serum albumin conjugated with molecular fluorophores and biotin. The synthesis steps and fluorescence emission of plasmonic-fluor was characterized by UV–vis spectroscopy, transmission electron microscopy, and fluorescence microscopy. Plasmon-enhanced competitive assay can be completed within 20 min and exhibited more than 30-fold lower limit-of-detection for cortisol compared to conventional competitive ELISA. The plasmon-enhanced competitive immunoassay when implemented as partition-free digital assay enabled further improvement in sensitivity. Further, spatially multiplexed plasmon-enhanced competitive assay enabled the simultaneous detection of two analytes (cortisol and fluorescein). This simple, rapid, and ultrasensitive method can be broadly employed for multiplexed detection of various small molecules in research, in-field and clinical settings.
KW - Competitive assay
KW - Multiplexed detection
KW - Plasmonic enhanced fluorescence
KW - Small molecule detection
UR - http://www.scopus.com/inward/record.url?scp=85122355494&partnerID=8YFLogxK
U2 - 10.1016/j.bios.2021.113918
DO - 10.1016/j.bios.2021.113918
M3 - Article
C2 - 34990957
AN - SCOPUS:85122355494
SN - 0956-5663
VL - 200
JO - Biosensors and Bioelectronics
JF - Biosensors and Bioelectronics
M1 - 113918
ER -