Glycolonitrile (HOCH2CN) is an attractive interstellar prebiotic molecule. Glycolonitrile is considered not only as a possible precursor for glycine but also as a key intermediate for adenine formation. Recently, HOCH2CN was detected toward IRAS 16293−2422 B with the Atacama Large Millimeter/submillimeter Array (ALMA). In this study we perform a comprehensive modeling study on HOCH2CN chemistry under the physical conditions of IRAS 16293−2422 B’s cold envelope and hot corino evolutions using the astrochemical code NAUTILUS and the updated gas-grain chemical network. Our studies not only give the main reactions and the favorable physical conditions for the formation of HOCH2CN but also uncover that the observed glycolonitrile in the cold envelope originates from the gradual accumulation of the gas-phase molecules during the ambient cloud, freefall collapse, and warm-up phases of the cold envelope evolution, and in the hot corino it mainly comes from the accumulated ices during the hot corino evolution. Using the updated chemical network, we also conduct chemical simulations under the physical conditions of Sagittarius (Sgr) B2(N) evolution. The simulation results show that varying the cosmic-ray ionization rate is needed to best reproduce the observational upper limits of HOCH2CN and the observed abundances of CNCHO and CH2CNH toward Sgr B2(N). Moreover, we predict that HOCHCNH, OCH2CN, HOCHCN, HOCCNH, OCCNH, and OCCN have high abundances and may be detectable toward IRAS 16293−2422 B and Sgr B2(N).
A new rhodol-derived fluorescent probe 1 with picolinate as the recognition receptor was designed and simply synthesized using a one-step reaction. With the concentration of added Cu 2+ increases, it gradually turns pink, so the effect of naked eye detection can be achieved. The detection limit of probe 1 for Cu 2+ is 42 nM, and the linear detection range was 0-2 μM. The experimental results showed that 1 was a fluorescent probe with high selectivity, good water solubility, and high sensitivity to Cu 2+ . Probe 1 was successfully applied in cell imaging experiments and can detect the concentration of Cu 2+ in water samples. All these indicate that probe 1 has the potential to be applied to the detection of Cu 2+ concentration in the real environment.
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