No abstract

In this paper, a novel rare-earth-doped upconverted nanomaterial NaYF4:Yb,Tm fluorescent probe is reported, which can detect cancer-related specific miRNAs in low abundance. The detection is based on an upconversion of nanomaterials NaYF4:Yb,Tm, with emissions at 345, 362, 450, 477, 646, and 802 nm, upon excitation at 980 nm. The optimal Yb3+:Tm3+ doping ratio is 40:1, in which the NaYF4:Yb,Tm nanomaterials have the strongest fluorescence. The NaYF4:Yb, Tm nanoparticles were coated with carboxylation or carboxylated protein, in order to improve their water solubility and biocompatibility. The two commonly expressed proteins, miRNA-155 and miRNA-150, were detected by the designed fluorescent probe. The results showed that the probes can distinguish miRNA-155 well from partial and complete base mismatch miRNA-155, and can effectively distinguish miRNA-155 and miRNA-150. The preliminary results indicate that these upconverted nanomaterials have good potential for protein detection in disease diagnosis, including early cancer detection.

MicroRNA-155 (miRNA-155) as a characteristic myeloma-associated biomarker exhibits significant potential application in the diagnosis of multiple myeloma (MM). In this paper, a novel type of molecular beacon (MB)-functionalized monolayer MoS2 nanosheet probe was proposed as fluorescent probe for high-sensitive assays of miRNA-155that uses a duplexspecificnuclease (DSN) enzyme to amplify the fluorescence signal. The preparation and detection conditions of the fluorescent probes were optimized in some aspects, such as the concentration of MoS2 (0.80 μM) and DSN (0.2 U), and the incubation time of DSN (30 min). The probesexhibited a sensitive fluorescence response to miRNA-155 and the fluorescence signal of the assay was significantly amplified by the cleavage of DSN. The relationship between F/F0 and logC miRNA follows a linear calibration curve, and the limit of detection (LOD) of miRNA-155 in 10% human serum is calculated to be 10.96 fM based on this relationship. The good performance and fluorescence amplification effect of the fluorescent probe were confirmed by studying the recovery of miRNA-155 in 10% human serum, which was ranged from 98.32% to 106.3% with a relative standard deviation of less than 4.14%. Besides, the high expression of miRNA-155 in clinic blood of MM patients was sensitively distinguished from healthy peoples by using the proposed probes. The proposed novel fluorescent probe based on the DSN can be used to detect miRNA-155 in human serum and provide a potential, convenient and reliable tool for diagnosis of MM.