The high-efficiency PEC material prepared by porphyrin grafted with Au nanoparticles embedded in porous carbon for PTK-7 detection

Abstract

Photoelectrochemical (PEC) analysis has attracted accumulated attention on diagnosis of diseases and high-efficiency photosensitizers are urgently needed. In this work, N-doped sheet-like porous carbon (N-PC) was prepared by thermal stripping of Zn2+ from zeolitic imidazole framework-8 (ZIF-8), followed by in situ formation of gold nanoparticles (Au NPs) embedded in the N-PC (termed Au NPs@N-PC). Also, the zinc meso-tetra (4-carboxyphenyl) porphine (ZnP) behaved as photosensitizer, which was covalently linked with Au NPs@N-PC (ZnP-Au NPs@N-PC), achieving the 9.2-fold enhancement in the photocurrents by using dopamine (DA) as donor. Next, the PEC mechanism was strictly discussed by UV–vis diffuse reflectance (DLS) spectroscopy, fluorescence (FL) and density functional theory (DFT) calculations. By virtue of the excellent PEC property, a label-free “signal off” PEC aptasensor was constructed based on the ZnP-Au NPs@N-PC for ultrasensitive detection of protein tyrosine kinase (PTK-7). The established biosensor showed a wider linear range of 10.00 pg mL−1 to 1.00 μg mL−1 (R2 = 0.99) and a lower limit of detection (LOD, 1.42 pg mL−1), coupled by showing acceptable results for diagnosis of gliomas. Hence, this research opens a valuable avenue for synthesis of advanced photosensitizer and holds huge potential in biomedical field.