A Simple and Effective Visual Fluorescent Sensing Paper-Based Chip for the Ultrasensitive Detection of Mercury Ions in Environmental Water

Abstract

Traces of mercury ions in environmental water can harm humans and animals. Paper-based visual detection methods have been widely developed for the rapid detection of mercury ions; however, existing methods are not sensitive enough to be used in real environments. Here, we developed a novel, simple and effective visual fluorescent sensing paper-based chip for the ultrasensitive detection of mercury ions in environmental water. CdTe-quantum-dots-modified silica nanospheres were firmly absorbed by and anchored to the fiber interspaces on the paper’s surface to effectively avoid the unevenness caused by liquid evaporation. The fluorescence of quantum dots emitted at 525 nm can be selectively and efficiently quenched with mercury ions, and the ultrasensitive visual fluorescence sensing results attained using this principle can be captured using a smartphone camera. This method has a detection limit of 2.83 µg/L and a fast response time (90 s). We successfully achieved the trace spiking detection of seawater (from three regions), lake water, river water and tap water with recoveries in the range of 96.8–105.4% using this method. This method is effective, low-cost, user-friendly and has good prospects for commercial application. Additionally, the work is expected to be utilized in the automated big data collection of large numbers of environmental samples.

The Analytical Application of Quenching Phenomena of CdTe Quantum Dot Nanoparticles

“…This was visible by using fluorescence microscopy, and some preliminary results have already been published elsewhere [48]. To improve the hydrophilicity of CdTe QD nanoparticles and their immobilization on strip paper, the preparation of silica-modified nanoparticles is recommended [29]. Using the luminescent nanocomposite LaF 3 :Ln 3+ /CdTe QD system [49], improvement in the chemosensor for detection of metal ions can also be achieved.…”

“…Their exceptional physicochemical and optical properties can be tuned, and they also exhibit higher photostability compared to organic fluorophores [1][2][3][4][5][6][7]. Thus, they can be used in optoelectronics [9], for the development of new analytical methods, for the sensitive detection and determination of ions and molecules important in biology and medicine [7,8,[14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33]. CdTe QD-based nanoparticles exhibit broad excitation and narrow emission bands where their position depends on their type, morphology, and size.…”

Integrated microfluidic platforms for heavy metal sensing: a comprehensive review

“…The LOD was found to be 2.83 μg L −1 . 75 Although CdTE/CdS QDs are sensitive in fluorescence detection, they are highly toxic to the environment. ZeSe QDs show less toxicity than CdTe QDs.…”

Porphyrin-Grafted Poly(ethylene terephthalate) as a Reusable and Highly Selective Colorimetric Probe for Mercuric Ion Contaminants in Aqueous Samples

“…Recent advancements have led to the creation of several Hg 2+ sensors, utilizing probes like metal oxo-clusters, , Au/Ag nanoparticles, , quantum dots, polymers, and metal–organic frameworks, with quantification methods that are generally based on the material’s fluorescence, UV–vis absorbance, electrochemistry, or surface plasmon resonance. , Only a small percentage of the published papers, however, reported on sensors that can also be amenable to actual onsite monitoring by utilizing a perceptible change in the material’s property such as its color. − …”