Photofuel cell-based self-powered biosensor for HER2 detection by integration of plasmonic-metal/conjugated molecule hybrids and electrochemical sandwich structure.

Human epidermal growth factor receptor 2 (HER2) has been regarded as the considerable biomarker of breast and gastric cancer. Thus, precise detection of HER2 is of significance for the early diagnosis and treatment. Here, a photofuel cell-based self-powered biosensor (PFC-SPB) was constructed for the ultrasensitive HER2 detection, which was composed of a plasmonic gold nanoparticles (Au NPs)/organic semiconductor hybrid photoanode and a cathode with biosensing strategy of electrochemical sandwich structure. The localized surface plasmon resonance effect of Au NPs can obviously enhance the separation efficiency of photo-generated electron/hole pair, which was beneficial to the sensitivity and stability of PFC-SPB. Meanwhile, the cathodic sandwich structure not only was used for the target recognition, but also can guarantee the enrichment of electroactive molecules (molybdophosphate). Consequently, with the open circuit voltage (E) as the output signal, the PFC-SPB can achieve the HER2 detection in the range of 0.1-500 pg mL with a low detection limit of 0.02 pg mL. Moreover, the as-proposed bioassay can be applied in cell lysate sample without any pretreatment, providing a promising and powerful tool early clinical diagnosis of cancer.