Photoelectrochemical determination of alkaline phosphatase activity based on a photo-excited electron transfer strategy

Publication date: 1 May 2019

Source: Talanta, Volume 196

Author(s): Jiuying Tian, Yanting Yang, Mingjuan Huang, Chunhong Zhou, Jusheng Lu

Abstract

A sensitive photoelectrochemical (PEC) biosensor for determination of alkaline phosphatase (ALP) activity was constructed based on a photo-excited electron transfer strategy. Immobilization of CdTe quantum dots (QDs) on TiO₂ nanotube arrays (TNAs), addition of iron (III) and adenosine triphosphate (ATP) in turn can effectively adjust the photocurrent response of TNAs under visible light irradiation due to a photo-excited electron transfer process, and alkaline phosphatase (ALP) activity can be determined for its catalysis toward dephosphorylation of ATP. The preparation of CdTe QDs, construction of TNA/QD PEC biosensor and the mechanism of photo-excited electron transfer are investigated in the present work. Under the optimal experimental conditions, the TNA/QD PEC biosensor shows a low limits of detection (LODs) (0.05 U L⁻¹) and limits of quantification detection (LOQs) (0.15 U L⁻¹), wide linear range from 0.2 to 15 U L⁻¹, and good selectivity towards ALP determination, which has been successfully applied for human serum analysis with good precision (RSD ≤ 5.4%) and high accuracy (recovery rate, 91–112%).

Graphical abstract

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