Organic-inorganic photoelectrochemical sensor based on aza-cope rearrangement reaction for formaldehyde

Abstract A photoelectrochemical (PEC) sensor was designed by connecting an organic recognize group 1-(4-(3-aminopropoxy)phenyl)-N-(4-nitrobenzyl)but-3-en-1-amine (FOP-1) to a modified photoelectric nanomaterial Pt-BiVO4 nano flowers (NFs) for ultra-sensitive and highly selective detection of formaldehyde (FA). The steric hindrance of the FOP-1 and the strong electron-withdrawing group nitro blocked the transfer of electrons excited to the electrode under illumination, resulting in a decrease in photocurrent. With the addition of FA, it triggered a specific aza-cope remake reaction (2-aza-cope sigmatropic rearrangement), leading to N-(4-nitrobenzyl)but-3-en-1-amin (NBEA) group removed, the steric hindrance weakened, the electron-withdrawing effect decreased, and the photocurrent signal recovered obviously. The entire sensor shows good stability and repeatability, excellent selectivity for FA, its detection limit is 0.4 μM, and the linear range is 1 to 1000 μM, Moreover, endogenous FA released from live MCF-7 cells and the real mice serum samples were monitored successfully by the PEC sensor, indicating its practicality potential in biological cytology and pathophysiology.