Based On Mn-ZnS Quantum Dots Phosphorescence Energy Transfer And Biosensing

Room-temperature phosphorescence (RTP) can be defined as radiativetransition originating from the lowest excited triplet state, T1, to the groundsinglet state, S0. As a very useful signal transduction method, RTP hasgained significance for optical sensing applications because it displaysmany advantages over steady-state fluorescence methods. Such as: longphosphorescence life, high sensitivity, more efficient approach forelimination of background fluorescence, etc.Despite the advantages offered by RTP detection, its most importantdrawback, which limits the development of new RTP-sensing systems, isthe lack of suitable phosphorescence indicators for a given analyte.As a result, the preparation of a new type of phosphorescencequantum dots and apply it is of great significance in the field of biologicalsensing. The details are as follows:1. An efficient phosphorescence energy transfer between quantum dots andcarbon nanotubes for ultrasensitive turn-on detection of DNA.We develop an efficient PET-based DNA biosensor using Mn-dopedZnS quantum dots conjugated with capture ssDNA (cDNA–QDs) andsingle-walled carbon nanotubes (CNTs) as the energy donor–acceptor pair for the first time. These results indicate that the cDNA–QDs–CNT sensingsystem has good selectivity down to singlebase mismatch. Therefore, thesystem can well discriminate tDNA and mDNA, and provide goodanti-interference ability. Under the optimum conditions, the linear range is0-45nM, the detection limit（3σ/k）is0.027nM.2. Aptamer-Based Turn-On Detection of Thrombin in Biological FluidsBased on Efficient Phosphorescence Energy Transfer from Mn-Doped ZnSQuantum Dots to Carbon Nanodots.In the proposed PET system, Mn-doped ZnS quantum dots (Mn-ZnSQDs) and carbon nanodots (CNDs) are used as energy donors andacceptors, respectively. Recently, MnZnS QDs have attracted considerableinterest and have been used as promising room-temperaturephosphorescence probes for optosensors due to the long-lived RTPemission of Mn-ZnS QDs that allows autofluorescence and scattering lightto be avoided. Under the optimum conditions, the linear range is0-40nM,the detection limit（3σ/k）is0.013nM.3. Graphene Surface-Anchored Phosphorescence Sensor for SensitiveDetection of MicroRNA Coupled with Enzyme-Free Signal Amplificationof Hybridization Chain Reaction.We report for the first time that small miRNAs are well-suited toefficiently initiate HCR and subsequently, grapheme oxide (GO) can be used to completely quench the phosphorescence of singlephosphorescence-labeled hairpin probes. Meanwhile, the hybridizationchain reactio（nHCR）products can maintain strong phosphorescence. Underthe optimum conditions, the linear range is0-0.05nM.