Visual electrochemiluminescence ratiometry on bipolar electrode for bioanalysis

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Nanotechnology

Background:

• Prostate cancer is a significant health concern, necessitating sensitive and accurate diagnostic tools.
• Current detection methods for prostate specific antigen (PSA), a key biomarker, face limitations in sensitivity and ease of use.
• Electrochemiluminescence (ECL) offers a sensitive detection platform, but visual and ratiometric approaches are needed for improved clinical utility.

Purpose of the Study:

• To develop a visual electrochemiluminescence (ECL) ratiometry for sensitive and accurate detection of prostate specific antigen (PSA).
• To utilize a closed bipolar electrode (BPE) array chip integrated with cadmium telluride quantum dots (CdTe QDs) and luminol for ratiometric signal generation.
• To employ gold nanorods (Au NRs) nanocomposite as a sensing probe for PSA detection via aptamer recognition.

Main Methods:

• Synthesis of highly efficient CdTe QDs emitting red light at the BPE cathode.
• Integration of luminol as an anodic ECL emitter for red-blue ratiometric ECL emission in BPE array chips.
• Assembly of Au NRs nanocomposite on the cathode surface to quench CdTe QDs ECL and promote luminol ECL, which is then released upon PSA binding.

Main Results:

• A visual red-blue ratiometric ECL signal was achieved on the BPE array chip.
• The Au NRs nanocomposite detachment upon PSA incubation led to partial recovery of cathode ECL and tắt of anode ECL.
• Sensitive PSA detection was demonstrated with a linear range of 1.0 ng/mL to 1.0 μg/mL and a detection limit of 0.5 ng/mL (S/N=3).

Conclusions:

• The developed BPE-ECL ratiometry provides an accurate and intrinsic method for PSA sensing.
• The visual ratiometric detection strategy shows significant potential for clinical diagnosis of prostate cancer.
• This approach combines the advantages of BPE-ECL and visual ratiometry for enhanced biomarker detection.