MnO2 nanosheet quenched thulium doped photon-up conversion luminescent immunoprobe for the ‘turn-on’ detection of cardiac troponin T

• Published in: Talanta (Oxford) 2024-08, Vol.275, p.126096-126096, Article 126096
• Main Authors: Abraham, Merin K., Madanan, Anju S., Varghese, Susan, Shkhair, Ali Ibrahim, Indongo, Geneva, Rajeevan, Greeshma, S, Vijila N., George, Sony
• Format: Article
• Language: English
• Subjects: Biosensor; Blue emitting up conversion nano probe; cTnT; FRET; Thulium up-conversion nanoparticle; Two dimensional nanosheet
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2024.126096

A “turn-on” photon up conversion nano couple based on NaYF4: Yb, Tm UCNPs quenched with MnO2 nanosheet was developed for the rapid and selective detection of cTnT. Herein, MnO2 nanosheet hold on the surface of Antibody cTnT (Ab-cTnT) conjugated blue emitting up conversion nanoprobe (λem at 475 nm), which leads to quenching of fluorescence due to energy transfer from photon up conversion nanoparticles to MnO2 nanosheets. On introducing cTnT antigen to the system, the energy transfer process is hindered due to strong antigen -antibody interface on the surface. This in turn, influences the nano-couples positions and effectively separates up conversion nanoprobe from MnO2 nanosheets surface resulting in restriction to energy transfer process enabling fluorescence recovery. The developed probe shows a linear response towards cTnT in the range of 0.16–2.77 ng/mL with a Limit of Detection (LoD) of 0.025 ng/mL. The practical feasibility of the nanoprobe is performed with possible coexisting biomolecules. Biological study in human blood serum samples exhibited sufficient recovery percentage in the range of 92–103 % is obtained. [Display omitted] •Blue emitting Thulium doped photon-upcoversion nanoprobe coupled with MnO2NS for the detection of cTnT was developed.•Surface modification with PEI to form PEI@NaYF4: Yb, Tm UCNPs.•Ab-cTnT is conjugated on the surface of PE1@ NaYF4: Yb, Tm UCNPs via. EDC-NHS coupling.•The luminescence intensity of the immunoprobe is quenched by the addition of nanosheet.•The luminescence intensity is “turn-on” with linear response from 0.016 to 2.7 ng/mL with a LoD of 0.025 ng/mL.