Xin Tan,Pu Zhang,Cuiying Ye,Yuanhong Min,Qianwen Li,Yi Wang
Development of new methods for dopamine (DA) assay has attracted continuous attention because it serves a vital role in clinical treatment of neurological diseases such as depression, schizophrenia, and Parkinson's disease. Herein, we design a carbon dots (CDs)-MnO 2 nanosheets platform for rapid and sensitive detection of DA in pharmaceutical products. The photoluminescence of CDs can be quenched by MnO 2 nanosheets via inner filter effect (IFE) because the absorption of MnO 2 nanosheets fully covered the excitation and emission bands of CDs. However, DA can transform MnO 2 nanosheets into Mn 2+ ions, resulting in the elimination of the IFE and recovery of the photoluminescent signal. This sensing platform shows a selective and sensitive response to DA in the range of 1–30 μM, with a detection limit of 100 nM. The presented IFE-based strategy gives a new insight on development of label-free, selective and sensitive optical methods for drug assay.
Osteoarthritis (OA) has become a serious problem to the human society for years due to its high economic burden, disability, pain, and severe impact on the patient’s lifestyle. The importance of current clinical imaging modalities in the assessment of the onset and progression of OA is well recognized by clinicians, but these modalities can only detect OA in the II stage with significant structural deterioration and clinical symptoms. Blood vessel formation induced by vascular endothelial growth factor (VEGF) occurs in the early stage and throughout the entire course of OA, enables VEGF relating gene sequence to act as a biomarker in the field of early diagnosis and monitoring of the disease. Here in, a facile rapid detection of VEGF relating ssDNA sequence was developed, in which manganese-based zeolitic imidazolate framework nanoparticles (Mn-ZIF-NPs) were synthesized by a simple coprecipitation strategy, followed by the introduction and surficial absorption of probe ssDNAs and the CRISPR/Cas12a system components. Furthermore, fluorescence experiments demonstrated that the biosensor displayed a low detection limit of 2.49 nM, a good linear response to the target ssDNA ranging from 10 nM to 500 nM, and the ability of distinguishing single nucleotide polymorphism. This finding opens a new window for the feasible and rapid detection of ssDNA molecules for the early diagnose of OA.