High Fructose Concentration Increases the Fluorescence Stability of DNA-Templated Copper Nanoclusters by Several Thousand Times

Abstract

DNA-templated copper nanoclusters (CuNCs) have limited applications because of their low fluorescence stability (several tens of minutes). In this study, we prepared CuNCs with improved temporal fluorescence stability by introducing fructose into the CuNC synthesis process and optimizing the reaction conditions. The inclusion of fructose increased the operating lifetime of CuNCs by approximately 5200-fold from 30 min to 108 days and improved their stability against heat, acids, and bases compared to CuNCs synthesized under original conditions. In addition, the fluorescence signal of CuNCs was maintained for a significantly longer time when stored at refrigeration (4 °C) and freezing (−20 °C) temperatures. Importantly, this method did not require the addition of substances other than fructose or any additional physicochemical treatment to maintain the fluorescence of DNA-templated CuNCs for more than several tens of days. As such, this study could serve as a basis to improve the stability of CuNCs for various applications.

Chloride Ligands on DNA-Stabilized Silver Nanoclusters

“…DNA-stabilized silver nanoclusters (Ag N -DNAs) are a diverse class of emitters that hold promise for bioimaging and biosensing. − Ag N -DNAs have been reported with wide-ranging emission wavelengths from 400 to 1200 nm, , emission lifetimes from nanoseconds to microseconds, − and favorably high quantum yields and extinction coefficients. − The combinatorial nature of DNA ligand sequences is responsible for the diversity of Ag N -DNA emitters, with nucleobase sequence selecting Ag N composition and photophysical properties. , These emitters can exhibit dark states that enable optically activated delayed fluorescence (OADF), , dielectric sensitivity, and quantum beating . Many Ag N -DNAs have been reported to undergo analyte-induced transformations that enable chemical sensing schemes, and a growing class of near-infrared (NIR)-emissive Ag N -DNAs ,, hold promise for NIR bioimaging. ,− …”

Micron-Scale Fabrication of Ultrathin Amorphous Copper Nanosheets Templated by DNA Scaffolds

“…In addition, the detected photoluminescence intensity of DNS/CuNSs was found to be stable within 5 h, compared to 2 h for dsDNA/CuNCs (Figure S19). The increased photostability may be attributed to the fact that DNSs are more stable than the dsDNA, resulting in DNA templates in DNS being less vulnerable to the • OH attack during Cu oxidation . The average fluorescence lifetime of DNS/CuNSs and dsDNA/CuNCs was determined to be 19.02 and 0.73 ns, respectively (see Figure S20 and Table S3).…”

Sensitive Urine Immunoassay for Visualization of Lipoarabinomannan for Noninvasive Tuberculosis Diagnosis

“…As high sensitivity plays a critical role here to enable a urine test of LAM, we have vigorously studied various approaches. A variety of signal amplification approaches have been reported for high detection sensitivity. − Among them, using inorganic metal nanoparticles (NPs) or luminescent nanomaterials such as QDs as signal reporters have emerged as efficient approaches to improve sensitivity. − However, the fluorescence emission of the DNA-templated Cu NPs could only be stable for a short time . Therefore, we further transduced the DNA-Cu NPs into QDs and calcein to generate stable visual fluorescence.…”

“…19−24 However, the fluorescence emission of the DNA-templated Cu NPs could only be stable for a short time. 25 Therefore, we further transduced the DNA-Cu NPs into QDs and calcein to generate stable visual fluorescence. In addition, considering that the colorimetric reading may be difficult for people with achromatopsia and anomalous trichromatism, 26,27 we made paper test strips printed with QDs and calcein to transduce test results into visual lengths of the strips as readouts (Scheme 1A).…”