Highly selective and sensitive determination of uranyl ion by the probe of CdTe quantum dot with a specific size

Determination of trace amounts of uranyl ions is of great significance to environment and human health, but challenging. In this paper, we demonstrate a new approach for highly effective determination of uranyl ions by the probe of CdTe quantum dot (QD) with a specific size. The selectivity is relied on the probe of CdTe quantum dots; the selectivity, which was a function of QDs size, was optimum at 6.8 nm. The probe has a detection limit of 7.88 × 10^-9 mol L^-1 and responded linearly to uranyl ion concentration in the range of 2.36 × 10^-8 mol L^-1 ~ 4.00 × 10^-7 mol L^-1. The mechanism can be probably attributed to the fact that uranyl ions could react with Te(0) on the surface of the quantum dots as large as 6.8 nm, resulting in fluorescence quenching. This work provides a new approach to detect uranyl ions in the aqueous solution by doing strip and real sample tests, and indicated the promise of this approach for real-time and in-situ detection of uranyl ions.