Gold nanoparticle-based nano-probe for the colorimetric sensing of Cr³⁺and Cr₂O₇²⁻by the coordination strategy

Abstract

In this work, an N-T/gold nanoparticle system was assembled for the convenient and colorimetric identification of Cr based on its coordination chemistry with the thymine derivative (N-T). In addition to the visible colorimetric changes for the qualitative Cr identification, the A values changed linearly with Cr concentration over a range of 0.5-2.5 μM and the detection limits reached 0.03 μM and 0.07 μM for Cr and CrO, respectively, both of which satisfied the Cr water quality standards of the U.S. EPA, WHO and China. Furthermore, a more convenient method was developed for quantitative determination of Cr concentrations in practical samples based on the Eyedropper function in Microsoft's PowerPoint software, wherein the RGB (red, green and blue) value of the sample could be easily screened in the colorimetric card for a more accurate result with good recovery, avoiding complicated instrumentation.

Sonochemical synthesis of polyoxometalate-stabilized gold nanoparticles for point-of-care determination of acetaminophen levels: preclinical study in an animal model

“…The extraordinary development of smartphones and tablets has made a great opportunity for researchers to develop their methods by using smartphones as a chemical detector. 46 These highly reliable portable devices which have a digital camera and internal microprocessor for image processing, reduce using external computers and expensive devices. 46 In this work, to obtain the calibration curve by analyzing the average RGB (red, green, and blue) value, the pictures of different concentrations of AP samples were taken.…”

“…46 These highly reliable portable devices which have a digital camera and internal microprocessor for image processing, reduce using external computers and expensive devices. 46 In this work, to obtain the calibration curve by analyzing the average RGB (red, green, and blue) value, the pictures of different concentrations of AP samples were taken. To verify the reliability of the smartphone as a chemical detector, we used two methods for analyzing the color changes.…”

Ultrasensitive point-of-care biochemical sensor based on metal-AIEgen frameworks

“…Chromium is a trace element necessary for life. Cr 3+ disorder (either deficiency or excess) is correlated to diabetes, cardiovascular diseases, and kidney toxicity (67)(68)(69). The gold standard of chromium (Cr 3+/6+ ) in drinking water set by the U.S. Environmental Protection Agency is less than 100 g/liter (or 1.92 M).…”

Ex vivo identification of circulating tumor cells in peripheral blood by fluorometric “turn on” aptamer nanoparticles

“…The as-prepared AuNPs with controlled size around 13 nm were the reduction product of gold ions by citrate. 49 In order to stabilize AuNPs in a nonaggregated state in biological systems, PEG-derivatives, acting as a passivation layer, were coated onto the nanoparticles. Two classes of PEG thiols have been utilized: (1) SH-PEG 5000 -N 3 possessing an azide group that could react with the acetylene DHA via click chemistry; (2) SH-PEG 5000 -NH 2 offering an amino group to link with NHS-PEG-MAL, which possesses maleimide to react with SH-DNA double strands.…”