L-cysteine capped ZnS:Mn quantum dots for room-temperature detection of dopamine with high sensitivity and selectivity

Abstract

Dopamine (DA) is one of the most important catecholamine neurotransmitters of the human central nervous system, and is involved in many behavioral responses and brain functions. Below normal DA levels in biological fluids can lead to different neurodegenerative conditions. For excess DA levels, a failure in energy metabolism is indicated. In this study, a facile room-temperature phosphorescence sensor is developed to detect DA based on l-cysteine capped Mn doped ZnS quantum dots (l-cys ZnS:Mn QDs). The QDs display a prominent orange emission band peaking at ~598nm, which is strongly quenched upon addition of DA in alkaline medium. The sensor exhibits a linear working range of ~0.15-3.00μM, and a limit of detection of ~7.80nM. These results are explained in terms of a pH-dependent electron transfer process, in which the oxidized dopamine quinone functions as an efficient electron acceptor. The QDs-based sensor shows a high selectivity to DA over common interfering biomolecules (including some amino acids, ascorbic acid, chloride and glucose). The sensor has been successfully applied for the detection of DA in urine samples, yielding recoveries as high as 93%. Our findings indicate that our developed sensor exhibits high sensitivity and reproducibility to determine DA even in biological fluids where DA is at low levels, e.g., in the central nervous system, which is the usual clinical profile of a neurodegenerative disorder associated to the Parkinson's disease.

Near-infrared turn-on fluorescent probe for discriminative detection of Cys and application in in vivo imaging

“…In recent years, various methods (including highperformance liquid chromatography, 7,8 mass spectrometry, 9,10 capillary electrophoresis, 11 optical sensing, [12][13][14][15] and electrochemical methods 16 ) for detecting Cys have been proposed on the basis of the close relationship between endogenous Cys and health of living organisms. However, traditional methods have inevitable disadvantages, such as high detection cost, long detection time, complicated pretreatment, and limited applications in vivo.…”

Effect of silica on the ZnS nanoparticles for stable and sustainable antibacterial application

“…Recently, II‐VI semiconductor nanoparticles are playing consideration in biomedical fields due to their exceptional biocompatibility and unique antibacterial properties. Zinc sulfide (ZnS) is highly biocompatible, direct wide bandgap (3.61 eV) vital semiconducting material for antibacterial action …”

Development of an Fe3O4@Cu silicate based sensing platform for the electrochemical sensing of dopamine

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] Among them, the development of dopamine (DA) sensors has drawn much attention, since DA, a vital neurotransmitter existing in the central nervous system of mammals, plays a signicant role in physiological process regulation. 17 Typically, either a deciency or large excess of DA in human serum is associated with several diseases, [18][19][20] which urges the development of highly sensitive methods for the detection of DA. So far, a variety of methods, including chromatography, 21 uorometry, 22 chemiluminescence analysis, 23 colorimetry, 24 and electrochemical assays 25 etc.…”