Paper-based gold nanoparticles decorated SWCNTs chemiresistive sensor for sensitive detection of As(III) based on electrochemical doping

A paper-based chemiresistive sensor consisting of a single-walled carbon nanotubes network with electro-deposited gold nanoparticles (AuNPs-SWCNTs) was developed for the sensitive detection of As(III). A new sensing strategy was also proposed combined with a paper-based device for As(III) chemiresistive detection based on the electrochemical doping of As(0) on the AuNPs-SWCNTs channel. The proposed paper-based chemiresistive sensor was manufactured by wax printing and vacuum deposition using a water-based SWCNTs ink. The sensor sensitivity was enhanced by optimizing the volume of SWCNTs ink used in the formation of the sensing network in the paper and the sweep segment of cyclic voltammetry used for the electrochemical deposition of AuNPs. Additionally, the mechanism of the sensing strategy based on the electrochemical n-doping of As(0) to the AuNPs-SWCNTs sensing channel was investigated using a liquid-ion gated FET system. The As(III) concentration detected by the as-fabricated chemiresistive sensor is as low as 1.35 x 10(-5) mu M which is even lower than the maximum permissible concentration in drinking water defined by the WHO. In this paper, we provide a simple strategy for developing paper-based chemiresistive sensors with unique properties for practical As(III) determination.

Automated summary

A paper-based chemiresistive sensor was developed for sensitive detection of As(III) by using a single-walled carbon nanotubes network with electro-deposited gold nanoparticles (AuNPs-SWCNTs). A new sensing strategy based on the electrochemical doping of As(0) on the AuNPs-SWCNTs channel was proposed. The sensor sensitivity was enhanced by optimizing the volume of SWCNTs ink used in the formation of the sensing network and the sweep segment of cyclic voltammetry used for the electrochemical deposition of AuNPs. The as-fabricated chemiresistive sensor can detect As(III) concentration as low as 1.35 x 10(-5) mu M, even lower than the maximum permissible concentration in drinking water defined by the WHO.