NAD(P)H Quinone Oxidoreductase 1 (hNQO1) is a cytosolic flavin two-electron reductase involved in many physiological and pathological processes that is overexpressed in many cancers and recognized as a potential cancer biomarker. However, it is still challenging for highly sensitive and selective monitoring hNQO1 in living cells. Here, we developed a highly selective and ultrasensitive hemicyanine-based near-infrared (NIR) fluorescence probe (probe HCYSN) for the sensing of hNQO1 activity and discrimination of human cancer cells. The fluorescent sensing system with NIR emission is low phototoxic to normal cells but is highly selective and ultrasensitive to hNQO1 in a linear range from 0.03 μg/mL to 0.6 μg/mL with detection limit (LOD) of 4.9 ng/mL (0.49 mU/mL), which is better than most of other hNQO1 probes reported. In particular, the NIR fluorescent probe was successfully applied to distinguish various cancer cells through the different distribution of endogenous hNQO1. All the present results demonstrated that the probe HCYSN exhibited great potential for human hNQO1 assay and in vivo imaging for the early cancers diagnosis and pathological studies.

中文翻译：

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用于超灵敏检测 hNQO1 活性和鉴别人类癌细胞的半花青基近红外荧光探针

NAD(P)H 醌氧化还原酶 1 (hNQO1) 是一种胞质黄素双电子还原酶，参与许多生理和病理过程，在许多癌症中过度表达，并被公认为潜在的癌症生物标志物。然而，对活细胞中的高灵敏度和选择性监测 hNQO1 仍然具有挑战性。在这里，我们开发了一种高选择性和超灵敏的基于半花青素的近红外 (NIR) 荧光探针（探针 HCYSN），用于检测 hNQO1 活性和区分人类癌细胞。具有 NIR 发射的荧光传感系统对正常细胞的光毒性低，但对 hNQO1 具有高度选择性和超敏感，线性范围为 0.03 μg/mL 至 0.6 μg/mL，检测限 (LOD) 为 4.9 ng/mL (0.49 mU/ mL)，这比报告的大多数其他 hNQO1 探针要好。特别是，NIR荧光探针通过内源性hNQO1的不同分布成功应用于区分各种癌细胞。所有目前的结果表明，探针 HCYSN 在人类 hNQO1 检测和早期癌症诊断和病理研究的体内成像方面表现出巨大的潜力。