Keywords
fluorometric detection
Si quantum dots
SiQDs
optical probe
hydrothermal method
How to Cite
Abstract
In this report, silicon quantum dots (SiQDs) with the NH2 functional group were synthesized with the hydrothermal method. The as-prepared SiQDs exhibit a strong fluorescence emission peak at 441 nm when excited at 355 nm and are effectively quenched upon adding Cr6+ ions. Hence, SiQDs were used as an optical probe to detect Cr6+ ions in solutions. The crystal structure of SiQDs was characterized by using X-ray diffraction (XRD). The Fourier-transform infrared spectroscopy (FT-IR) was used to determine the linker groups on the SiQDs surface. The fluorescence spectroscopic technique with an excitation wavelength of 355 nm was used to quantify the Cr6+ ion concentration in the solutions in the range of 0.1–1000 µM. Competition from common coexisting ions, such as K+, Na+, Al3+, Zn2+, and Pb2+, was ignorable. The test with actual samples showed good linearity for the Cr6+ concentration range of 0.1–50 µM.
References
- Dupont L, Guillon E. Removal of hexavalent chromium with a lignocellulosic substrate extracted from wheat bran. Environ Sci Technol. 2003;37:4235-41.
- Fendorf SE. Surface reactions of chromium in soils and waters. Geoderma. 1995;67:55-71.
- Pechova A, Pavlata L. Chromium as an essential nutrient: A review. Vet Med (Praha). 2007;52:1-18.
- Costa M. Potential hazards of hexavalent chromate in our drinking water. Toxicol Appl Pharmacol. 2003;188:1-5.
- Onchoke KK, Sasu SA. Determination of Hexavalent Chromium (Cr(VI)) Concentrations via Ion Chromatography and UV-Vis Spectrophotometry in Samples Collected from Nacogdoches Wastewater Treatment Plant, East Texas (USA). Adv Environ Chem. 2016;2016:1-10.
- 6. Shrivastava R, Upreti RK, Chaturvedi UC. Various cells of the immune system and intestine differ in their capacity to reduce hexavalent chromium. FEMS Immunol Med Microbiol. 2003;38:65-70.
- Flury B, Eggenberger U, Mäder U. First results of operating and monitoring an innovative design of a permeable reactive barrier for the remediation of chromate contaminated groundwater. Appl Geochemistry. 2009;24:687-96.
- Ragosta M, Caggiano R, D’Emilio M, Macchiato M. Source origin and parameters influencing levels of heavy metals in TSP, in an industrial background area of Southern Italy. Atmos Environ. 2002;36:3071-87.
- Zazo JA, Paull JS, Jaffe PR. Influence of plants on the reduction of hexavalent chromium in wetland sediments. Environ Pollut 2008;156:29-35.
- Resch-Genger U, Grabolle M, Cavaliere-Jaricot S, Nitschke R, Nann T. Quantum dots versus organic dyes as fluorescent labels. Nat Methods. 2008;5:763–75.
- Lewinski N, Colvin V, Drezek R. Cytotoxicity of nanopartides. Small. 2008;4:26-49.
- Cheng X, McVey BFP, Robinson AB, Longatte G, O’Mara PB, Tan VTG, et al. Colloidal silicon quantum dots: from preparation to the modification of self-assembled monolayers for bioimaging and sensing applications. Colloid Nanoparticles Biomed Appl XII. 2017;10078: 100780O.
- Phan LMT, Baek SH, Nguyen TP, Park KY, Ha S, Rafique R, et al. Synthesis of fluorescent silicon quantum dots for ultra-rapid and selective sensing of Cr(VI) ion and biomonitoring of cancer cells. Mater Sci Eng C. 2018;93:429-36.
- Terada S, Xin Y, Saitow KI. Cost-Effective Synthesis of Silicon Quantum Dots. Chem Mater. 2020;32:8382-92.
- Wang X, Yang Y, Huo D, Ji Z, Ma Y, Yang M, et al. A turn-on fluorescent nanoprobe based on N-doped silicon quantum dots for rapid determination of glyphosate. Microchim Acta. 2020; 187.
- Holmes JD, Ziegler KJ, Doty RC, Pell LE, Johnston KP, Korgel BA. Highly luminescent silicon nanocrystals with discrete optical transitions. J Am Chem Soc. 2001;123:3743-8.
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