Electrochemical aptamer biosensor for As³⁺ based on apta deep trapped Ag-Au alloy nanoparticles-impregnated glassy carbon electrode

ABSTRACT

Arsenic is toxic, so being able to detect and monitor arsenic in aqueous environments is important. Here, we report a biosensor for As³⁺ (Arsenic (III)) which uses a glassy carbon electrode modified with Ag-Au alloy NPs (i.e. Silver and gold alloy nanoparticles) and loaded with an aptamer. The electrode contains apta deep trapped Ag-Au alloy NPs, and the detection method employs cyclic voltammetry and differential pulse voltammetry. Captured As³⁺ ions undergo electrochemical reaction, producing a significant increase in the current which is observed in the voltammetry curves. This current increase is a result of the electrocatalytic properties of the NPs. The electrode is used for the determination of As³⁺ in real water samples. The activity curve is linear for As³⁺ concentrations of 0.01µg/L to 10 µg/L, and the detection limit is 0.003 × 10⁻³µg/L. The operation of the biosensor is reproducible, stable, and selective, and the biosensor performs well in determining As³⁺ in water from natural water courses, lakes, and wells.

KEYWORDS:

• Ag-Au alloy
• apta deep trapped
• glassy carbonelectrode
• arsenic

Acknowledgements

The authors are thankful to Edanz Group (www.edanzediting.com/ac) for editing a draft of this manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the University Grand Commission (UGC), New Delhi, [Award No RGNF-2014-15D-OBC-UTT-67233] and this research was jointly supported by the Department of Science and Technology (DST), New Delhi India and Russian Science Foundation (RSF), Moscow, Russia [project # 19-44-02020].