Photon upconversion immunoprobe based on resonance energy transfer for brain natriuretic peptide – A prognostic biomarker for heart failure

Schematic representation of sensing of BNP antigen using the upconversion probe AuNS@Ab@PAA@Mn-NaYF4:Yb/Er UCNPs. [Display omitted] •Developed a photon upconversion-based immunoprobe for detecting Brain Natriuretic Peptide (BNP), a heart failure biomarker.•Probe utilizes resonance energy transfer (RET) between Mn2+ ions doped NaYF4:Yb/Er upconversion nanoparticles (UCNPs) and gold nanostars (AuNS).•Specific antigen–antibody interactions induce turn-on luminescence response upon BNP detection.•Exhibits high sensitivity with detection range of 30 pg/mL–303 pg/mL and low detection limit of 1.76 pg/mL.•Capable of detecting BNP in human serum within a 10-min incubation with a recovery percentage of 83.76 %–112.94 %. Brain Natriuretic Peptide (BNP) holds significant clinical importance as a biomarker for heart-related conditions aiding in diagnosis, prognosis and monitoring of heart failure, providing valuable insights for timely intercession and patient management. Photon upconversion nanomaterials exhibit captivating ability to convert low energy photons to high energy ones, enabling enhanced sensitivity in sensing application. In this perspective, we develop a new photon upconversion based immunosensor for the detection of a heart failure biomarker, Brain Natriuretic Peptide (BNP) by Resonance Energy Transfer (RET) between Polyacrylic acid capped Mn2+ ions doped NaYF4:Yb/Er Upconversion Nanoparticles (PAA@Mn-NaYF4:Yb/Er UCNPs) as the donor and gold nanostar (AuNS) as the acceptor. BNP antibody was conjugated on the surface of PAA@Mn-NaYF4:Yb/Er UCNPs. The immunosensor can produce strong turn on luminescence intensity in proportional to increasing BNP antigen concentration through specific antigen–antibody interactions. The proposed photon upconversion based immunosensor can achieve turn on behaviour in the linear range from 30 pg/mL to 303 pg/mL with a Limit of Detection (LOD) of 1.76 pg/mL. The immunosensor exhibited appreciable selective and sensitive response towards BNP.