We developed a near-infrared (NIR) electrochemiluminescence (ECL) immunosensor for sensitively and selectively determining carbohydrate antigen 125 (CA125) with toxic-element-free and environmental-friendly AgInS 2 /ZnS nanocrystals (NCs) as tags. The core/shell-structured AgInS 2 /ZnS NCs not only can be conveniently prepared via an aqueous synthetic procedure, but also has high photoluminescence quantum yield (PLQY) of up to 61.7%, highly monodispersed, water-soluble, and desired biological compatibility. As AgInS 2 /ZnS NCs can be oxidized via electrochemically injecting holes into their valence band at + 0.84 V, both the monodispersed AgInS 2 /ZnS NCs in solution and the surface-confined AgInS 2 /ZnS NCs immobilized in sandwich-typed immuno-complexes with CA125 as analyte can exhibit efficient oxidative-reduction ECL around 695 nm under physiological conditions with the presence of tri-n-propylamine (TPrA). The ECL intensity from the AgInS 2 /ZnS NCs immobilized in sandwich-typed immuno-complexes increases linearly and selectively with an increased concentration of CA125 from 5 × 10 −6 to 5 × 10 −3 U/mL, and limit of detection (LOD) was 1 × 10 −6 U/mL (S/ N = 3). This reliable platform can provide an effective detection method in the early diagnosis and treatment of ovarian cancer. Graphical abstract
Low-toxicity, highly luminescent, and water-soluble AgInS2/ZnS nanocrystals (NCs) have been synthesized via a microwave-assisted approach. The structure and optical features of the AgInS2/ZnS NCs were characterized by X-ray diffraction, high resolution transmission electron microscopy, Fourier transform infrared spectroscopy, ultraviolet visible absorption spectroscopy and photoluminescence (PL) spectroscopy. The as-synthesized AgInS2/ZnS NCs exhibited high PL quantum yields (40%) and long PL lifetimes (424.5 ns). Furthermore, the dynamic changes of the intracellular copper(II) levels in HeLa cells were monitored using the AgInS2/ZnS NCs as fluorescent probes. The results showed that the AgInS2/ZnS NCs as promising fluorescent probes can be used in the detection of intracellular copper ions in living cells.
危险品化学品经营许可证（带存储）