1 research outputs found
Attomolar Determination of Coumaphos by Electrochemical Displacement Immunoassay Coupled with Oligonucleotide Sensing
Coumaphos, an organophosphorus pesticide (OP) used worldwide,
has
raised serious public concerns due to its positive association with
major types of cancer. Herein, a novel method for attomolar coumaphos
detection was developed on the basis of an electrochemical displacement
immunoassay coupled with oligonucleotide sensing. An optimized displacement
immunoassay was constructed to improve the binding efficiency of an
antigen–antibody pair, and a guanine-rich single-strand DNA
label, in combination with oligonucleotide sensing, was used to amplify
the detection signal with “direct” relationship to the
analyte. As a result, coumaphos was sensitively determined from the
enhanced catalytic cycle of guanine-RuÂ(bpy)<sub>3</sub><sup>2+</sup> by chronoamperometry. The limit of detection (LOD) was down to 0.18
ng L<sup>–1</sup> (S/N = 3), which is equal to 49.6 amol in
a sample solution of 100 ÎĽL. In comparison with conventional
methods, the proposed method has the lowest LOD and better accessibility
to high-throughput sensing systems. Besides, it can complete the whole
analysis process in under 50 min and exhibits good performance of
excellent selectivity to the OPs. With regard to the advantages of
rapidity, convenience, low cost, and ease of operation, the proposed
method has provided a promising platform capable of fast and in-field
OP detection, which may make the system promising for potential applications
in the detection of other small molecules