Sensitive detection of tumor necrosis factor-alpha (TNF-α) in human serum is beneficial for finding cancer patients early due to overexpressed TNF-α being related to some cancers. Here, a photoelectrochemical (PEC) aptasensor was constructed for ultrasensitive TNF-α assay based on the signal generator of hollow CdS cubes (H-CdS) and the signal extinguishing activity of NiCo 2 O 4 -Au. In this work, compared with traditional solid CdS, H-CdS could greatly promote the PEC signal because its hollow structure could accelerate the separation of photogenerated charges, which also possesses abundant active sites and high light absorption capability. Moreover, H-CdS can be prepared facilely with Cd-based Prussian blue analogs as the precursor. Meanwhile, NiCo 2 O 4 -Au was fabricated and utilized as a signal extinguisher. In the presence of TNF-α, NiCo 2 O 4 -Au could be introduced onto the H-CdS modified electrode, producing competitive consumption of the electron donor effect, the p-n semiconductor quenching effect, and the mimetic enzymatic catalytic precipitation effect, which all can significantly reduce the PEC signal. Based on the signal extinguishing activity of NiCo 2 O 4 -Au and the signal generator of H-CdS, TNF-α can be detected sensitively with a lower detection limit (0.63 fg mL -1 ) and a wide linear range (1 fg mL -1 - to 1 ng mL -1 ), which may have a potential application in the PEC bioanalysis field and the disease diagnostics field.
Keyphrases
- quantum dots
- sensitive detection
- rheumatoid arthritis
- loop mediated isothermal amplification
- visible light
- energy transfer
- label free
- hydrogen peroxide
- nitric oxide
- reduced graphene oxide
- gold nanoparticles
- molecular docking
- room temperature
- mass spectrometry
- molecularly imprinted
- drug induced
- tandem mass spectrometry