The Coordination of Pyridyl-N to Pentacyanoferrate for the Electrochemical Detecting Small Organic Molecules

Abstract

The coordination of pyridyl-N to pentacyanoferrate for the detection of small organic antigens in solution is presented. The unique contribution of this paper is the direct conjugation of pyridyl-N in small organic antigens to pentacyanoferrate. Pentacyanoferrate is promising as an electrochemical label owing to its good electrochemical properties, which can be utilized to generate an electrical signal in homogeneous electrochemical immunoassays. The facilely synthesized pyridyl-N to pentacyanoferrate was characterized by the electrochemical and spectroscopic methods. Hippuric acid (HA) has been detected competitively on the interaction of free HA and pentacyanoferrate-(4-aminomethylpyridine-hippuric acid) (Fe-HA) to its antibody, with the detection limit of 0.50 µg mL −1. While pentacyanoferrate-based immunoassay is in its simplicity and infancy, the proposed immunoassay offers attractive opportunities for developing pyridyl-N-based the electrochemical detection of small organic antigens in the health care area.

A Simple Interfacial Platform for Homogeneous Electrochemical Immunoassays Using a Poly(Vinylimidazole)-Modified Electrode

“…Phosphate buffered saline (PBS, 4.3 mm NaH 2 PO 4 , 15.1 mM Na 2 HPO 4 , and 140 mM NaCl) and all other solutions were prepared using deionized Milli-Q water (Milli-Q ® Acdemic, Molsheim, France). PVI and [Fe(CN) 5 (amp-HA)] 3−/2− (Fe-HA) were prepared by adapting the previously reported procedures [ 17 , 18 , 33 ]. Analytical grade reagents were used without further purification.…”

“…Moreover, the ferricyanide redox complex has been used for the determination of various target substrates because of its reversible redox system [ 15 , 16 ]. Pentacyanoamminferrate(III) which has five cyanide groups and one amine complexed with an Fe(III) ion, has a similar structure and electrical characterictics as the ferricyanide redox complex, therefore a small molecule having imidazole and pyridine rings can be replaced by the amine group of pentacyanoamminferrate [ 17 , 18 ].…”

Heterogeneous Electrochemical Immunoassay of Hippuric Acid on the Electrodeposited Organic Films

“…The complex of [Fe(CN) 5 (amp-HA)] 3−/2− (Fe-HA) was synthesized as described previously [ 34 ]. Fifty milligrams of Na 2 [Fe(CN) 5 NH 3 ]·2H 2 O and 44.4 mg of amp-HA were dissolved in 60 mL of aqueous ethanol solution (v/v: 50/50) and kept at room temperature for 24 h. After filtering, the solution was added to 2.0 L of diethyl ether with vigorous stirring.…”