ABSTRACT
BACKGROUND: Oncological analysis is important in tumor diagnosis. We constructed a dual-fluorescence and binary visual analysis system for circulating tumor cells (CTCs) using the folate receptor as a biomarker, combined with hybridization chain reaction and nanomaterial amplification. This strategy integrates terminal protection, selective recognition properties of N-methyl mesoporphyrin IX and CdTe quantum dots for Cu2+ and double-stranded templated copper nanoparticles, and inkjet printing technology. RESULTS: In fluorescence mode, folate receptor and A2780 ovarian cancer cells were specifically detected with a limit of detection of 0.1 fg mL-1, and 10 cells mL-1 were observed. The detection limits of both the color and distance reading modes were comparable to those obtained in fluorescence mode. The applicability of the method for quantifying CTCs was validated using 27 (6 negative and 21 positive) clinical ovarian cancer samples; the results agreed with those of both the clinical folate receptor-polymerase chain reaction kit and radiological and pathological results. SIGNIFICANCE: This dual-fluorescence and binary visual CTCs detection method provides multiple options for clinical tumor liquid biopsy.
Subject(s)
Cadmium Compounds , Neoplastic Cells, Circulating , Ovarian Neoplasms , Tellurium , Humans , Female , Ovarian Neoplasms/pathology , Ovarian Neoplasms/diagnosis , Ovarian Neoplasms/blood , Neoplastic Cells, Circulating/pathology , Tellurium/chemistry , Cadmium Compounds/chemistry , Quantum Dots/chemistry , Cell Line, Tumor , Copper/chemistry , Fluorescence , Fluorescent Dyes/chemistry , Biomarkers, Tumor/blood , Limit of Detection , Porphyrins/chemistryABSTRACT
We synthesized Cu single atoms embedded in a N-doped porous carbon catalyst with a high Faradaic efficiency of 93.5% at -0.50 V (vs. RHE) for CO2 reduction to CO. The evolution of Cu single-atom sites to nanoclusters of about 1 nm was observed after CO2 reduction at a potential lower than -0.30 V (vs. RHE). The DFT calculation indicates that Cu nanoclusters improve the CO2 activation and the adsorption of intermediate *COOH, thus exhibiting higher catalytic activity than CuNx sites. The structural instability observed in this study helps in understanding the actual active sites of Cu single atom catalysts for CO2 reduction.