A visible and near-infrared light dual responsive signal-off and signal-on photoelectrochemical aptasensor for prostate-specific antigen

A visible and near-infrared light dual responsive signal-off and signal-on photoelectrochemical aptasensor was constructed for determining prostate-specific antigen (PSA) based on MoS2 nanoflowers and gold nanobipyramids. The dual responsive photoelectrochemical aptasensor can provide accurate results for PSA determination. For the photoelectrochemical aptasensor fabrication, amino-group functionalized aptamers were immobilized on a MoS2 nanoflowers modified glassy carbon electrode surface for the specific recognition, and thus to achieve a signal-off aptasensor for PSA under visible light illumination. Subsequently, gold nanobipyramids integrated with thiol-functional aptamer were introduced to the signal-off aptasensing interface after PSA recognition. Under excitation with near-infrared light at 808 nm, the photocurrent response can be amplified significantly due to the excellent conductivity and local surface plasmon resonance effect of gold nanobipyramids, thus to producing a signal-on model for determining PSA. Under the optimized conditions, the dual-responsive photoelectrochemical aptasensor shows a linear response to the logarithm of PSA concentration in the range of 0.005-100 ng/mL. The detection limits for PSA determination with a signal-off or a signal-on mode are 1.75 pg mL(-1) and 0.39 pg mL(-1), respectively. The dual-responsive photoelectrochemical aptasensor was also employed for determining PSA in clinical serum samples with satisfactory selectivity and excellent accuracy.

Automated summary

A visible and near-infrared light dual-responsive aptasensor was developed for accurate determination of prostate-specific antigen (PSA) using MoS2 nanoflowers and gold nanobipyramids. The aptasensor exhibited signal-off and signal-on responses, providing a wide linear range and low detection limits for PSA determination. Clinical serum samples were successfully analyzed with satisfactory selectivity and excellent accuracy using this dual-responsive aptasensor.