Ag-Mediated DNA Nanomachine Cascade Nanomaterial Amplification Enable One-Pot Electrochemical Analysis of Circulating Tumor DNA.

Circular tumor DNA (ctDNA) is a trace nucleic acid that functions as an essential tumor marker. In this context, the present study proposes a one-pot electrochemical analysis of ctDNA EGFR L858R in lung cancer leveraging a Ag-mediated DNA nanosphere (I amplification) and cation exchange reaction (II amplification), and Cu acts as a signal molecule. Once the target L858R exists, it specifically destroys the structure of DNA nanosphere@Ag, and large amounts of Ag are released.

Self-Assembled DNA Machine and Selective Complexation Recognition Enable Rapid Homogeneous Portable Quantification of Lung Cancer CTCs.

In this study, we systematically investigated the interactions between Cu and various biomolecules, including double-stranded DNA, Y-shaped DNA nanospheres, the double strand of the hybridization chain reaction (HCR), the network structure of cross-linked HCR (cHCR), and small molecules (PPi and His), using Cu as an illustrative example. Our research demonstrated that the coordination between Cu and these biomolecules not only is suitable for modulating luminescent material signals through complexation reactions with Cu but also enhances signal intensities in materials based on chemical reactions by increasing spatial site resistance and local concentration. Building upon these findings, we harnessed the potential for signal amplification in self-assembled DNA nanospheres and the selective complexation modulation of calcein in conjunction with the aptamer targeting mucin 1 as a recognition probe.

Biomolecules-mediated electrochemical signals of Cu: Y-DNA nanomachines enable homogeneous rapid one-step assay of lung cancer circulating tumor cells.

This study presents a straightforward efficient technique for extracting circulating tumor cells (CTCs) and a rapid one-step electrochemical method (45 min) for detecting lung cancer A549 cells based on the specific recognition of mucin 1 using aptamers and the modulation of Cu electrochemical signals by biomolecules. The CTCs separation and enrichment process can be completed within 45 min using lymphocyte separation solution (LSS), erythrocyte lysis solution (ELS), and three centrifugations. Besides, the influence of various biomolecules on Cu electrochemical signals is comprehensively discussed, with DNA nanospheres selected as the medium.

Sensitive Urine Immunoassay for Visualization of Lipoarabinomannan for Noninvasive Tuberculosis Diagnosis.

Lipoarabinomannan (LAM) is a prospective noninvasive biomarker for tuberculosis (TB) diagnosis. Here, we report a visual immunoassay of high sensitivity for detecting LAM in urine samples toward TB diagnosis. This method uses a DNA-linked immunosorbent of LAM, followed by a transduction cascade into amplified visual signals using quantum dots (QDs) and calcein reaction with Cu and copper nanoparticles (Cu NPs).

Fluorescence Aptasensor of Tuberculosis Interferon-γ in Clinical Samples Regulated by Steric Hindrance and Selective Identification.

Although there are many interferon gamma (IFN-γ)-based tools for tuberculosis (TB) diagnosis, they are less sensitive and laborious. Here, we developed an IFN-γ aptasensor using pyrophosphate-cerium coordination polymeric nanoparticles (PPi-Ce CPNs) as signal reporters and a double-stranded DNA as a probe. The sensor was realized by sterically regulating the polymerization elongation of terminal deoxynucleotidyl transferase (TdT) and the selective recognition reaction of PPi-Ce CPNs.

Homogeneous Visual and Fluorescence Detection of Circulating Tumor Cells in Clinical Samples Selective Recognition Reaction and Enzyme-Free Amplification.

Here we report a simple all-nucleic-acid enzyme-free catalyzed hairpin assembly assisted amplification strategy with quantum dots (QDs) as the nanoscale signal reporter for homogeneous visual and fluorescent detection of A549 lung cancer cells from clinical blood samples. This work was based on the phenomenon that CdTe QDs can selectively recognize Ag and C-Ag-C and by using mucin 1 as the circulating tumor cells (CTCs) marker and aptamer as the recognition probe. Under optimized conditions, the limits of detections as low as 0.

Quantification of C, N labelled compounds with C, N edited H Nuclear Magnetic Resonance spectroscopy.

It was significant to detect isotope labelled compounds in biology and pharmacy. Based on a novel H Nuclear Magnetic Resonance (H-NMR) technique, a simple, fast and green method has been successfully established to quantitatively detect C, N isotope labelled compounds. In this protocol, the couples between H and C, N nearby were removed, which greatly simplified the spectrum.