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Download fileGold Nanostar Enhanced Surface Plasmon Resonance Detection of an Antibiotic at Attomolar Concentrations via an Aptamer-Antibody Sandwich Assay
journal contribution
posted on 2017-05-18, 00:00 authored by Suhee Kim, Hye Jin LeeA new
sandwich assay for tetracycline (TC) involving a DNA aptamer
and antibody pair is demonstrated in conjunction with gold nanostar
(GNS) enhanced surface plasmon resonance (SPR) to achieve detection
in the low attomolar range. GNS particles were covalently functionalized
with the antibody probe (antiTC) and integrated into a surface sandwich
assay in conjunction with a SPR gold chip modified with the TC-specific
aptamer. After it was demonstrated that both affinity probes can bind
simultaneously to TC, optimization of the assay was performed using
either antiTC only or GNS-antiTC conjugates to interact with aptamer/TC
complexes present on the chip surface. Target concentrations as low
as 10 aM could be detected using GNS-antiTC’s, which was >103 times greater in performance than when using antiTC only.
In addition, good selectivity was achieved with respect to other tetracycline
derivative antibiotics, such as oxytetracycline (OTC) and chlortetracycline
(CTC), both which are structurally similar to TC. As a demonstration
of trace antibiotic analysis in environmental samples, the GNS enhanced
sandwich assay was applied to analyze TC added to aliquots of local
river water and the results validated by comparing to conventional
high-performance liquid chromatography (HPLC) analysis.