Triple-Function-Intensified Photoelectric Immunosensing Platform for One-Step Detection of Cardiac Troponin I

Area of Science:

• Materials Science
• Nanotechnology
• Biosensing

Background:

• Semiconductor nanowires integrated with nanoplasmonic substrates offer real-time photocurrent responses for immunosensing.
• One-step biorecognition detection of cardiac troponin I (cTnI) remains a significant challenge in current immunosensing platforms.

Purpose of the Study:

• To develop an ultrasensitive immunosensor for one-step, label-free detection of cardiac troponin I (cTnI).
• To create a novel antenna-engaged nanowire-inspired porous heterostructure for enhanced photoelectric performance and signal amplification.

Main Methods:

• Fabrication of a polydopamine-functionalized titanium dioxide nanowire/Au plasmonic layer (PDA/TNW/Au-PL) heterostructure.
• Utilizing interfacial engineering of type II heterojunction and Schottky junction to improve electron-hole separation.
• Employing a nanowire-inspired PDA layer for enhanced charge carrier mobility and direct antibody binding.

Main Results:

• Achieved ultrasensitive, label-free cTnI detection within approximately 30 minutes.
• Demonstrated a wide linear sensing range from 0.001 to 1000 ng mL⁻¹ with an ultralow detection limit of 0.001 ng mL⁻¹.
• The PDA/TNW/Au-PL heterostructure exhibited enhanced light-harvesting efficiency and photoelectric performance.

Conclusions:

• The developed PDA/TNW/Au-PL immunosensor enables rapid, one-step detection of cTnI without secondary antibodies or labels.
• This platform shows significant potential for point-of-care diagnostics, facilitating immediate and accurate therapeutic decision-making.
• The triple-function signal intensification strategy offers a promising approach for developing advanced biosensing technologies.