Aptameric recognition-modulated electroactivity of poly(4-styrenesolfonic acid)-doped polyaniline films for single-shot detection of tetrodotoxin
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Date
2015
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
MDPI
Abstract
The work being reported is the first electrochemical sensor for tetrodotoxin
(TTX). It was developed on a glassy carbon electrodes (C) that was modified with
poly(4-styrenesolfonic acid)-doped polyaniline film (PANI/PSSA). An amine-end
functionalized TTX-binding aptamer, 5′-NH2-AAAAATTTCACACGGGTGCCTCGGCTGTCC-3′
(NH2-Apt), was grafted via covalent glutaraldehyde (glu) cross-linking. The resulting
aptasensor (C//PANI+/PSSA-glu-NH2-Apt) was interrogated by cyclic voltammetry (CV)
and electrochemical impedance spectroscopy (EIS) in sodium acetate buffer (NaOAc,
pH 4.8) before and after 30 min incubation in standard TTX solutions. Both CV and EIS
results confirmed that the binding of the analyte to the immobilized aptamer modulated the
electrochemical properties of the sensor: particularly the charge transfer resistance (Rct) of
the PANI+/PSSA film, which served as a signal reporter. Based on the Rct calibration curve
of the TTX aptasensor, the values of the dynamic linear range (DLR), sensitivity and limit
of detection (LOD) of the sensor were determined to be 0.23–1.07 ng·mL−1
TTX,
134.88 ± 11.42 Ω·ng·mL−1
and 0.199 ng·mL−1
, respectively. Further studies are being
planned to improve the DLR as well as to evaluate selectivity and matrix effects in
real samples.
Description
Keywords
Tetrodotoxin sensor, Aptamer, Polyaniline, Puffer fish
Citation
Fomo, G. et al. (2015). Aptameric recognition-modulated electroactivity
of poly(4-styrenesolfonic acid)-doped polyaniline films
for single-shot detection of tetrodotoxin. Sensors, 15: 22547-22560