A Novel Photoelectrochemical Platform for Detection of

A novel photoelectrochemical (PEC) biosensing platform was constructed for protease detection. Firstly, a short designed peptide that can be hydrolyzed selectively by a target protease was synthesized and combined on indium tin oxide (ITO) electrode surface. Then, the negatively charged PEC material, such as CdTe QDs, was subsequently immobilized on the electrode surface by means of electrostatic attraction to form a PEC biosensor, which can produce strong photocurrent under irradiation. Once the platform is incubated with target protease, the photocurrent would decrease. The decrease on photocurrent is relation to the concentration of target protease and incubating time. Based on this, the concentration of target protease can be detected selectively under the given incubating time. Take trypsin for example, a sensitive and selective biosensor for trypsin had been constructed. The biosensor possesses a linear response range of 0.3-24 μg/mL trypsin with a correlation coefficient of 0.9979 and a detection limit of 0.07 μg/mL based on a signal-to-noise ratio of 3