Simultaneous and sensitive determination of ascorbic acid, dopamine and uric acid via an electrochemical sensor based on PVP-graphene composite

Abstract

A method with high sensitivity, good accuracy and fast response is of ever increasing importance for the simultaneous detection of AA, DA and UA. In this paper, a simple and sensitive electrochemical sensor, which based on the polyvinylpyrrolidone (PVP)-graphene composite film modified glassy carbon electrode (PVP-GR/GCE), was presented for detecting ascorbic acid (AA), dopamine (DA) and uric acid (UA) simultaneously. The PVP-GR/GCE has excellent electrocatalytic activity for the oxidation of AA, DA and UA. The second-order derivative linear sweep voltammetry was used for the electrochemical measurements. The peak potential differences of DA-AA, DA-UA, and UA-AA (measured on the PVP-GR/GCE) were 212, 130 and 342 mV respectively. Besides, the over potential of AA, DA and UA reduced obviously, so did the peak current increase. Under the optimum conditions, the linear ranges of AA, DA and UA were 4.0 μM-1.0 mM, 0.02-100 μM, and 0.04-100 μM, respectively. The detection limits were 0.8 μM, 0.002 μM and 0.02 μM for AA, DA, and UA. The electrochemical sensor presented the advantages of high sensitivity and selectivity, excellent reproducibility and long-term stability. Furthermore, the sensor was successfully applied to the analysis of real samples.

Research on the fate of polymeric nanoparticles in the process of the intestinal absorption based on model nanoparticles with various characteristics: size, surface charge and pro-hydrophobics

“…Caco-2 cells in the logarithmic growth phase were seeded at 3 × 10 5 cells/well in a 6-well plate and grown for 48 h. The following inhibitors (2 mL) were then added: chlorpromazine (30 μmol/L), EIPA (20 μmol/L), formalin (20 μmol/L), and M-β-CD (2.5 mmol/L). After 0.5 h, fluorescent NPs (20 μg/mL) were added to the co-cultured cells, which were then incubated for 1 h. Following treatment as described above, the fluorescence intensity of the cells was measured by flow cytometry [ 7 , 8 ]. For the control group PBS was used instead of an inhibitor.…”

“…In the past 3 years, three new nano pharmaceutical preparations (Vyxeos, Onpattro, and Hensify) have been approved and represent a new generation of nano pharmaceutical preparations has successfully entered the market and opened up new clinical trials based on their unique physical and chemical properties. More than 50 nano pharmaceutical preparations have been approved for clinical use, and more than 400 are expected to become new clinical solutions alone or in combination with other key enabling technologies [5][6][7][8][9].…”

Detection of xanthine in food samples with an electrochemical biosensor based on PEDOT:PSS and functionalized gold nanoparticles

“…On the other hand, the electrochemical methods have several advantages like simple, portable, less time consuming, highly sensitive and no need of samples pretreatment over these traditional methods. [18][19][20][21][22][23][24] Electrochemical sensors for XA detection are able to meet all contemporary needs. The most common electrochemical methods for XA detection include multiwall carbon nanotube composite, 25 nanoporous carbon ber, 26 pretreated carbon paste, 27 preanodized nontronite-coated carbon, 28 and polymer lms.…”

Trace Analysis of Emerging Virus: an Ultrasensitive ECL-Scan Imaging System for Viral Infectious Disease

“…The protocols were based on the previous works. [39][40][41] The detailed synthetic routes of Ru(bpy)3 2+ was listed in Figure S2. The reactant of cis-dichlorobis(2,2'-bipyridine)ruthenium(II) with a excess of the corresponding 2,2′-bipyridine-4,4′-dicarboxylic acid (1:1.2) was refluxed in an ethanol/water (80 ％ ) mixture, and the mixture was incubated at 80 o C for one night to synthetize Ru(bpy)2(dcbpy)(PF6)2.…”

“…Herein, a dendritic polymer probe-amplified electrochemiluminescence (ECL) [40][41][42] scan imaging system was constructed to realize trace analysis of viral emerging infectious disease (Figure 1). Dendritic polymer probe was employed as the efficient signal giving-out component that could generate amplified ECL signal on the integrated chip.…”