Photofuel cell-based self-powered biosensor for HER2 detection by integration of plasmonic-metal/conjugated molecule...

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^OCV) as the output signal, the PFC-SPB can achieve the HER2 detection in the range of 0.1-500 pg mL^-1 with a low detection limit of 0.02 pg mL^-1. 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.