Conventional electrochemical sensors use voltammetric and amperometric methods with external power supply and modulation systems, which hinder the flexibility and application of the sensors. To avoid the use of an external power system and to minimize the number of electrochemical cell components, a self-powered electrochemical sensor (SPES) for hydrogen peroxide was investigated here. Iron phthalocyanine, an enzyme mimetic material, and Ni were used as a cathode catalyst and an anode material, respectively. The properties of the iron phthalocyanine catalyst modified by graphene nanoplatelets (GNPs) were investigated. Open circuit potential tests demonstrated the feasibility of this system. The GNP-modulated interface helped to solve the problems of aggregation and poor conductivity of iron phthalocyanine and allowed for the achievement of the best analytical characteristics of the self-powered H2O2 sensor with a low detection limit of 0.6 µM and significantly higher sensitivity of 0.198 A/(M·cm2) due to the enhanced electrochemical properties. The SPES demonstrated the best performance at pH 3.0 compared to pH 7.4 and 12.0. The sensor characteristics under the control of external variable load resistances are discussed and the cell showed the highest power density of 65.9 μW/cm2 with a 20 kOhm resistor. The practical applicability of this method was verified by the determination of H2O2 in blood serum.

Self-powered sensing platforms have received widespread attention in areas such as portable, wearable and point-of-care devices. Here we reported visible light mediated self-powered electrochemical sensing based on target induced recombination of photogenerated carriers, which has highly sensitive to detect copper ions concentration. We utilized the recombination of photogenerated carriers mechanism to design visible light-responsive Fe2O3-CdS n-n heterojunction as photoanode material, which greatly improved the problem of output energy in photocatalytic self-powered sensors. Expectedly, our proposed visible light mediated self-powered electrochemical system has high separation efficiency of photogenerated carriers, which is 8.4 times that in presence of Cu2+. Furthermore, this self-powered electrochemical sensing platform used Cu2+ induced recombination of photogenerated carriers, showed a clear linear relationship from 1 nM to 5000 nM with an acceptable detection limit of 0.4 nM. This self-powered electrochemical sensing platform with excellent selectivity, accredited reproducibility and believable stability exhibited promising prospects in developing portable sensing devices and detection chip for real-time and rapid monitoring of Cu2+.