Facile electrochemical/colorimetric platform based on electrochromic tungsten oxide film for sensitive/visual adenosine triphosphate detection

Abstract

In this paper, we present an electrochemical/colorimetric aptasensor based on tungsten oxide (WO3) film for rapid adenosine triphosphate (ATP) analysis. WO3 film was electrodeposited onto the surface of FTO substrate, and functioned in regulating conductivity and indicating color change of the aptasensor. For electrochemical impedance measurements, intercalation of Li+ ions in WO3 film could enhance its conductivity and thus decrease background signal. Compared with aptasensor under non-lithiated state, aptasensor under fully lithiated state exhibited a larger detection range, lower detection limit and superior selectivity. On the other hand, for colorimetric measurements, electrochromic behavior of the proposed aptasensor could be adjusted by the hinder effect induced by specific binding between aptamers and ATP. The proposed aptasensor provided both electrochemical and colorimetric detection modes, which combined the advantages of high sensitivity and simple readout. More importantly, this paper provides a simple strategy for enhancing the detection sensitivity of electrochemical sensors based on WO3 film, which holds a great significance in expanding the application of WO3 in electrochemical fields.