Electrochemiluminescent biosensor for Palytoxin detection based on CNTs surface modifications.
|Giovanni Valenti 1, Valeria A. Zamolo 2, Stefania Rapino 1, Alan Le Goff 2, Marco De Bortoli 2, Francesco Paolucci 1, Maurizio Prato 2, Massimo Marcaccio 1, Aurelia Tubaro 2|
1. University of Bologna, Dipartimento di Chimica "G. Ciamician" (UNIBO), via Selmi 2, Bologna 40126, Italy
Electrogenerated Chemiluminescence (ECL) is a redox induced emission. ECL is the processes whereby species generated at electrodes undergo high-energy electron transfer reaction to form excited states that emit light. Since its first application, the ECL technique, has become a very powerful analytical tool and has been widely used in biosensor transduction. The ECL presents an intrinsically low noise and high sensitivity; moreover, the electrochemical generation of the excited state prevents scattering of the light source: for all these characteristics, ECL is an elective technique for ultrasensitive immunoassay detection. The majority of ECL systems involve species in solution where the emission occurs in the diffusion layer near to the electrode surface. Over the past few years, an intense research has been focused on the ECL generated from species constrained on the electrode surface. Nowadays, more and more attention has been paid to ECL biosensors functionalized with nanomaterials due to the combination of the unique physical and chemical proprieties of the nanomaterial with the excellent aforementioned properties of ECL. In this context, the composite materials based on carbon nanotubes (CNTs) are particularly promising for sensing applications. In fact, an improvement in sensitivity and stability of ECL biosensors was obtained from the modification of the electrode surface with CNTs. Moreover, proteins and enzymes can be easily immobilized within or on the CNTs either by physical adsorption or covalent binding, often involving the carboxylic functionalities introduced onto the CNT surface by oxidizing procedures. In the present research we combined ECL transduction with the CNTs binding proprieties in order to design a new platform for the detection of Palytoxin (PTX). Palythoa toxica, is known as one of the most potent marine toxins: human illness and fatalities have been reported after ingestion of PTX-contaminated tropical and subtropical fish and crabs . Recently, considerable traces of PTX have been regularly registered in some areas of the Mediterranean Sea, provoking in 2005 more than 200 cases of respiratory syndrome in patients exposed to marine aerosol on beach areas in Genoa, Italy. Furthermore, these toxins have also been detected in seafood (mussels, clams and sea urchins) collected in the Mediterranean Sea. Due to the high toxicological potential of PTX and its analogs we have focused the present research on the realization of an electrochemiluminescent sensor device for the PTX detection; wile our platform is extremely versatile and can be modified to detect many other biological analyte.
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Presentation: Short communication at SMCBS'2009 International Workshop, by Giovanni Valenti
See On-line Journal of SMCBS'2009 International Workshop
Submitted: 2009-09-07 12:19 Revised: 2009-09-07 16:07