An ultra-sensitive electrochemical sensor for ascorbic acid based on click chemistry

Abstract

A highly selective and sensitive electrochemical sensor for ascorbic acid (AA) assay has been prepared through Cu(I) catalyzed azide-alkyne cycloaddition reaction (CuAAC). The catalyst, Cu(I) species, is acquired from the reduction of Cu(II) by AA in situ. In the presence of Cu(I) catalyst, the azide modified Au electrode surface is shown to react quantitatively with terminal propargyl-functionalized ferrocene forming 1,2,3-triazoles. The electrochemical response of propargyl-functionalized ferrocene modified Au electrode surface can be monitored using differential pulse voltammetry (DPV) technique. Under optimal conditions, it is found that the current intensity has a linear relationship with the logarithm of AA concentration in the range of 5.0 × 10(-12) to 1.0 × 10(-9) M. Furthermore, the proposed electrochemical sensor shows a good stability (RSD 4.2%), high selectivity and low detection limit for AA detection. In addition, it also demonstrates that the proposed sensor can be applied to detect AA in real urine samples with satisfactory results.

Recent Progress in Ferrocene-Modified Thin Films and Nanoparticles for Biosensors

“…Interesting procedures for immobilizing Fc on electrode surfaces, based on click chemistry [88,89] and boronate ester formation [90], have recently been reported. A Au electrode was modified with an azide-terminated self-assembled monolayer, to which alkyne-substituted Fc was added via a click reaction in the presence of Cu 2+ catalyst [88].…”

“…A Au electrode was modified with an azide-terminated self-assembled monolayer, to which alkyne-substituted Fc was added via a click reaction in the presence of Cu 2+ catalyst [88]. The corresponding Fc-modified electrode exhibited a strong response to ascorbic acid in the range of 5.0 × 10 −12 to 1.0 × 10 −9 M. Alternatively, azide-substituted Fc can be confined to an alkyne-modified surface [89].…”

Rapid extraction and quantitative detection of the herbicide diuron in surface water by a hapten-functionalized carbon nanotubes based electrochemical analyzer

“…Various nano-structured films have been used for the development of electrochemical sensors and biosensors, because of their synergistic effects on the electrochemical and catalytic activity. 16,17 Carbon nanotubes (CNTs) have recently gained interest for use in electrochemical immunoassays due to their remarkable tensile strength, surface area, flexibility and other unique structural, mechanical, electrical as well as physicochemical properties reflecting increased signal currents. 18,19 The possibility of functionalizing these smart nano-materials directly with different biomolecules and their biocompatibility make them extremely attractive for electrochemical based sensing.…”

Chemically-driven “molecular logic circuit” based on osmium chromophore with a resettable multiple readout

“…14 Notably, the evaluated detection limits (DL Cu 2+ ¼ 1.2 Â 10 À9 M and DL F À ¼ 2.8 Â 10 À6 M) are superior so far. 15 The repetitive action of a receptor is highly sought aer for molecular logic functions. The chemical information written on probe 1 by Cu 2+ and F À could be erased (>95% reversibility) by H 2 O (5 ml in 3 ml) or H + (5 ml, 10 À4 M, 3 ml), respectively (Fig.…”