Yameng Li,Peilin Wang,Huan Wang,Zhenrun Li,Zihui Liang,Qiang Ma
MiRNA-214 can regulate the expression of their downstream target genes after post-transcriptional and are involved in the biological processes of triple negative breast cancer (TNBC). In this work, the small-sized luminescent Nb 2 C nanosheet-based whispering gallery mode-enhanced electrochemiluminescence (ECL) strategy was successfully constructed to detect miRNA-214 in TNBC. Firstly, we have synthesized small-sized luminescent Nb 2 C nanosheets from Nb 2 AlC MXene. The Nb 2 C nanosheets not only exhibited more stable chemical properties and reduced the defects of the large sheet structures, but also possessed the quantum confinement effect with the discrete energy level. As a result, the prepared small-sized Nb 2 C nanosheets had unique luminescent and electrochemical properties. Furthermore, in order to improve the ECL performance of Nb 2 C nanosheets, SiO 2 microspheres were self-assembled on the electrode surface by gas-liquid interface method to form whispering gallery mode structure. Because the light was continuously reflected at the interface of the microcavity in the whispering gallery mode, the ECL signal of Nb 2 C luminescent nanosheets was amplified largely. Finally, the whispering gallery mode-based ECL sensing platform was established. The results showed that the biosensor had a good linear correlation between the ECL intensity and the logarithm of concentration of miRNA-214 in the range of 10 fM to 100 nM with a limit of detection of 2.5 fM. The actual detection of miRNA-214 content in clinical TNBC tissue samples was realized successfully.
Shuting Cheng,Huimin Liu,Hui Zhang,Guanglei Chu,Yemin Guo,Xia Sun
An ultrasensitive electrochemiluminescence (ECL) aptasensor for detection of kanamycin (KAN) was constructed by using the chemiluminescence properties of luminol-hydrogen peroxide (H 2 O 2 ) in alkaline solution. Silver nanoparticles (AgNPs) could act as effective catalyzer to accelerate H 2 O 2 decomposition to produce various intermediate reactive oxygen species for signal amplification and thus increased the ECL intensity of luminol. When the target KAN was in the presence, ECL signal decreased obviously owing to the specific interaction between KAN and aptamer. Thus, the concentration of KAN could be determined according to the intensity of ECL. To further demonstrate the effect of aptasensor, we had conducted cyclic voltammetry on an electrochemical workstation and electrogenerated chemiluminescence analyzer, respectively. Upon the optimization of assay conditions, the proposed aptasensor displayed a wide linear range from 0.5 to 100 ng mL −1 with limit of detection of 0.06 ng mL −1 . The as-proposed aptasensor was not only capable of achieving a satisfactorily low detection limit but also possessed advantages of excellent accuracy, specificity and stability. Furthermore, this constructed ECL sensing platform was successfully applied to detect KAN in real samples and it would be of excellent potential to detect other antibiotics using the proposed method.