A photoelectrochemical sensor based on CdTe NPs decorated copper-tetramine phthalocyanine covalently grafted graphene oxide for p-aminophenol determination

Objective: Para-aminophenol (PAP) is a critical intermediate widely used in medicine, pharmaceutical, rubber, antioxidant, petroleum, and other fields, but it is harmful to the environment. A novel photo electrochemical (PEC) sensor was synthesized and applied to detect PAP based on the composite material of cadmium telluride nanoparticle (CdTe NPs)-decorated copper-tetramine phthalocyanine covalently grafted graphene oxide (CuTAPc-Gr). Materials & Methods: Copper-tetramine phthalocyanine (CuTAPc) has an excellent PEC conversion effect and narrow band. Graphene (Gr) has high mechanical stability and suitable bandgap. CuTAPc-Gr was synthesized by chemical covalent bonding. And CdTe NPs@CuTAPc-Gr composite was prepared by ultrasonic mixing method using CuTAPc-Gr and CdTe NPs. The morphology and structure of the PEC materials were characterized using scanning electron microscopy and fourier transform infrared spectrometer. PAP contents were evaluated by the Time-Current method. And the electron transfer rate of the PEC sensor was studied by electrochemical impedance spectroscopy methods. Results & Discussion: CdTe NPs@CuTAPc-Gr has excellent PEC properties. In the PAP analysis, distinct regular changes in the photocurrent within a linear range of 33.3-1330.0 nM were noted. The limit of detection was 15.5 nM. Acetaminophen, phloroglucin, and other substances did not affect PAP content determination. The water samples were analyzed using the proposed PEC sensor. The results show that the recoveries were in the range of 97.85%-99.58%, and relative standard deviations (RSDs) were less than 2%. Conclusions: The PEC sensor exhibited excellent sensitivity, selectivity, and stability. The proposed method provides an effective strategy for constructing PEC sensors to detect PAP in water samples and a promising PEC platform for analyzing other small molecules.