Near-infrared-emitting NaYF4:Yb,Tm/Mn upconverting nanoparticle/gold nanorod electrochemiluminescence resonance energy transfer system for sensitive prostate-specific antigen detection.

An electrochemiluminescence resonance energy transfer (ECL-RET) system that detects prostate-specific antigen (PSA) was created. Near-infrared (NIR)-emitting NaYF4:Yb,Tm/Mn upconverting nanoparticles (UCNPs) are used as donors, and gold nanorods (GNRs) are used as acceptors. The ECL was enhanced nearly threefold by Mn2+ doping, with an emission peak appearing at an NIR wavelength of 808 nm. Anti-PSA 1 (Ab1) was bound to the surfaces of UCNPs after being modified with poly(acrylic acid) (PAA). As for acceptors, cetyltrimethylammonium bromide (CTAB)-capped GNRs were treated with 11-mercaptoundecanoic acid (MUDA) and then conjugated with Anti-PSA 2 (Ab2). When PSA was added, donors and acceptors were brought in close proximity through specific interactions of antibodies and antigens, resulting in high quenching efficiency levels. Under optimal conditions, the linear range of detection was 3.75-938 pg/mL for PSA (R = 0.999), with a detection limit as low as 3.16 pg/mL. This method can be applied to detect PSA in human serums with satisfactory results. Graphical abstract An electrochemiluminescence resonance energy transfer system was developed for determination of prostate-specific antigen using near-infrared-emitting NaYF4:Yb,Tm/Mn upconverting nanoparticles as donors and gold nanorods as acceptors.