Abstract:Both direct and non‐competitive two‐site (sandwich) immunoassays are reported for 3‐phenoxybenzoic acid (3‐PBA) utilizing signal transduction by electrochemical impedance spectroscopy (EIS), and the sandwich immunoassay reduces the detection limit for this small molecule analyte by ∼70×. The direct EIS immunoassay utilizes a polyclonal antibody to 3PBA for biomolecular recognition, while the sandwich EIS immunoassay utilizes in addition a previously reported antiimmunocomplex M13 bacteriophage clone. For both … Show more
A novel
ultrasensitive nanobody-based electrochemical immunoassay
was prepared for assessing human exposure to pyrethroid insecticides.
3-Phenoxybenzoic acid (3-PBA) is a common human urinary metabolite
for numerous pyrethroids, which broadly served as a biomarker for
following the human exposure to this pesticide group. The 3-PBA detection
was via a direct competition for binding to alkaline phosphatase-embedded
nanobodies between free 3-PBA and a 3-PBA-bovine serum albumin conjugate
covalently immobilized onto citric acid-decorated nylon nanofibers,
which were incorporated on a screen-printed electrode (SPE). Electrochemical
impedance spectroscopy (EIS) was utilized to support the advantage
of the employment of nanofibrous membranes and the success of the
immunosensor assembly. The coupling between the nanofiber and nanobody
technologies provided an ultrasensitive and selective immunosensor
for 3-PBA detection in the range of 0.8 to 1000 pg mL–1 with a detection limit of 0.64 pg mL–1. Moreover,
when the test for 3-PBA was applied to real samples, the established
immunosensor proved to be a viable alternative to the conventional
methods for 3-PBA detection in human urine even without sample cleanup.
It showed excellent properties and stability over time.
A novel
ultrasensitive nanobody-based electrochemical immunoassay
was prepared for assessing human exposure to pyrethroid insecticides.
3-Phenoxybenzoic acid (3-PBA) is a common human urinary metabolite
for numerous pyrethroids, which broadly served as a biomarker for
following the human exposure to this pesticide group. The 3-PBA detection
was via a direct competition for binding to alkaline phosphatase-embedded
nanobodies between free 3-PBA and a 3-PBA-bovine serum albumin conjugate
covalently immobilized onto citric acid-decorated nylon nanofibers,
which were incorporated on a screen-printed electrode (SPE). Electrochemical
impedance spectroscopy (EIS) was utilized to support the advantage
of the employment of nanofibrous membranes and the success of the
immunosensor assembly. The coupling between the nanofiber and nanobody
technologies provided an ultrasensitive and selective immunosensor
for 3-PBA detection in the range of 0.8 to 1000 pg mL–1 with a detection limit of 0.64 pg mL–1. Moreover,
when the test for 3-PBA was applied to real samples, the established
immunosensor proved to be a viable alternative to the conventional
methods for 3-PBA detection in human urine even without sample cleanup.
It showed excellent properties and stability over time.
As a major metabolite of pyrethroids pesticide, 3-phenoxybenzoic acid (3-PBA) can be an indicator of health risk and human exposure assessment. Based on nanobodies (Nbs), we have developed a rapid...
Hapten immunoassays have found extensive application across various domains such as disease diagnostics, environmental monitoring, as well as the evaluation of food and pharmaceutical safety. These techniques traditionally rely on...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.