Porphyrin-based covalent organic framework as bioplatfrom for detection of vascular endothelial growth factor 165 through fluorescence resonance energy transfer

Construction of bifunctional electrochemical biosensors for the sensitive detection of the SARS-CoV-2 N-gene based on porphyrin porous organic polymers

“…This finding suggests the successful preparation of TAPP-DPDD-POP via the condensation reaction. 19,48 In addition, an absorption peak located at 1619 cm −1 for TAPP-DPDD-POP is attributed to the stretching band of CvN, 46 further confirming the successful formation of imine linkage between TAPP and DPDD. The N 2 isotherm evaluation of the porphyrin-POP (Fig.…”

“…S3a, † only one main characteristic peak at 2θ = 19.3°is obtained, corresponding to the amorphous carbon. 19 This amorphous nanostructure and the rough surface of the TAPP-DPDD-POP structure are remarkably helpful for improv-Shaoming Fang is a professor in the School of Material and Chemical Engineering, Zhengzhou University of Light Industry. He obtained his Ph.D. at Hebei University of Technology, China.…”

“…11,12 Among these methods, the detection of the SARS-CoV-2 N-gene by using the targeted antibody or aptamer is the most efficient sensing approach via the formation of an antibody-N-gene complex 13,14 or G-quadruplex between the aptamer and N-gene. 15,16 Accordingly, various immunosensors and aptasensors have been integrated with surface plasmon resonance, 16 electrochemical, 17,18 fluorescence, 19 surface-enhanced Raman scattering, 15 lateral flow assay, 20 electrochemical techniques, 21,22 and colorimetry 23 for the biosensor construction via the formation of antigen-antibody or G-quadruplex complexes. Electrochemical biosensors (such as immunosensors and aptasensors) are considered as alternative and reliable sensing strategies for the analysis of the SARS-CoV-2 N-gene because of their fast response, high sensitivity, and feasible operation.…”

Aptamer‐based biosensors and application in tumor theranostics

“…The fluorescence signal is turned off based on FRET between the luminescent agent and the quencher 16,66 . When the target marker is present, the conformation switch shifts, the quencher and the fluorophore are separated, and the fluorescent signal is turned on again to quickly detect the target protein 67 (Figure 4A). This method of turning off and then turning on the fluorescent signal effectively reduces the background signal 3 .…”

“…This method of turning off and then turning on the fluorescent signal effectively reduces the background signal 3 . Common high‐distance‐dependent fluorescence signal quenchers include graphene oxide, mesoporous carbon nanospheres, organic frameworks, magnetic nanoparticles, etc 67‐70 . Xu et al designed a four‐color sensor based on FRET to distinguish 4 tumor markers, AFP, VEGF 165 , CEA and HER2, with a very low detection limit, 64 realizing the simultaneous detection and imaging of multiple tumor‐related proteins in living cells.…”