In this paper, we report a simple, sensitive and selective colorimetric visualization of dopamine (DA) using dithiobis(succinimidylpropionate) (DSP)-modified gold nanoparticles (AuNPs) as probes and ferric ions as cross-linkers. Via the standard amine coupling reaction between the amino groups of DA and activated carboxyl groups of DSP, DA molecules can be assembled onto the surface of DSP-AuNPs. Accordingly, Fe(3+) ions induce a change of DSP-AuNPs in color and UV-vis absorbance by coordinating to the catechol groups of the anchored DA. The pH dependence and mechanism of this method are discussed. A detection limit of 2 nM was obtained, which is lower than those achievable with currently used chromatographic and electrochemical techniques. The feasibility for the detection of DA in artificial cerebrospinal fluid has been demonstrated.
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http://dx.doi.org/10.1039/c2an35734h | DOI Listing |
Med Biol Eng Comput
December 2024
Department of Biomedical Engineering, Price Faculty of Engineering, University of Manitoba, 75 Chancellors Cir, Winnipeg, MB, R3T 5V6, Canada.
Spatial impairment characterizes Alzheimer's disease (AD) from its earliest stages. We present the design and preliminary evaluation of "Barn Ruins," a serious virtual reality (VR) wayfinding game for early-stage AD. Barn Ruins is tailored to the cognitive abilities of this population, featuring simple controls and error-based scoring system.
View Article and Find Full Text PDFMikrochim Acta
December 2024
Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan, 250022, People's Republic of China.
A novel detection technique is introduced that offers sensitive and reliable ochratoxin A (OTA) detection. The method leverages the etching of gold nanorods (AuNRs) stabilized by hexadecyl trimethyl ammonium bromide (CTAB) using the oxidized form of 3,3',5,5'-tetramethyl benzidine sulfate (TMB), creating a susceptible multicolor visual detection system for OTA. The visual detection is enabled by Mg-assisted DNAzyme catalysis combined with the catalytic hairpin assembly (CHA) signal amplification strategy.
View Article and Find Full Text PDFJ Chin Med Assoc
December 2024
Department of Emergency Medicine, The Third Clinical Medical College of Ningxia Medical University, Ningxia, Yinchuan, China The Third Clinical Medical College of Ningxia Medical University, Ningxia,Yinchuan, China.
Background: COVID-19, caused by SARS-CoV-2, has had a significant impact on global health. While the virus primarily affects the respiratory system, the intricate interplay between immune cells and the virus remains poorly understood. This study investigates the causal relationship between 731 immune cell phenotypes and COVID-19 using Mendelian randomization analysis.
View Article and Find Full Text PDFFood Chem
December 2024
State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China. Electronic address:
In this work, a series of three-dimensional (3D) SERS substrate were successfully fabricated by assembling silver nanoparticles (AgNPs) onto a porous gelatin sponge (GS) for highly sensitive thiram residues detection in vegetables. These 3D micro-nanostructures could induce the sufficient surface plasmon resonance (SPR) effect of noble metals on their surface and achieve high enrichment of pollutant molecules. As crystal violet (CV) was used as a probe molecule, the lowest CV solution could be detected at 10 M, and the enhancement factor (EF) was calculated to be 9.
View Article and Find Full Text PDFAnal Chem
December 2024
NMPA Key Laboratory for Research and Evaluation of Drug Metabolism & Guangdong Provincial Key Laboratory of New Drug Screening & Guangdong-Hongkong-Macao Joint Laboratory for New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515, China.
A simple, rapid, and visual approach is developed to perform diagnosis of urinary tract infection (UTI) and antimicrobial susceptibility testing (AST) by employing smart bifunctional DNA (bfDNA) sensors, exonuclease III, concatermers of CuO nanoparticles (CuONPs), and gold NPs (AuNPs) aggregation [AuNPs agglutination (AA)], namely, the bfDEC-AA method. The bfDNA sensors serve as probes for identifying 16S rRNA genes of bacterium or 18S rRNA of fungus and as mediators connecting the concatermers of CuONPs. The AA as a signal source is triggered by Cu(I)-catalyzed azide-alkyne cycloaddition click chemistry.
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