FisMat2017 - Submission - View

Abstract's title: ElectroSpray Deposition for biosensor application: instrument design and deposit analysis from ambient pressure to vacuum
Submitting author: Jacopo Chiarinelli
Affiliation: Università RomaTre - Dipartimento di Scienze// CNR-ISM
Affiliation Address: via G. Saragat n°20
Country: Italy
Oral presentation/Poster (Author's request): Poster
Other authors and affiliations: J. Chiarinelli ( CNR, Istituto di Struttura della Materia, Area della Ricerca di Roma 1, Monterotondo Scalo, Italy , Dipartimento di Scienze, Università di RomaTre, Roma, Italy) , M.C. Castrovilli ( CNR, Istituto di Struttura della Materia, Area della Ricerca di Roma 1, Monterotondo Scalo, Italy) , N. Cicco (CNR, Istituto di Metodologie per l’Analisi Ambientale, Zona Industriale - Tito Scalo (PZ), Italy) , P. Bolognesi ( CNR, Istituto di Struttura della Materia, Area della Ricerca di Roma 1, Monterotondo Scalo, Italy) , P. Calandra (CNR, Istituto per lo Studio dei Materiali Nanostrutturati, Area della Ricerca di Roma 1, Monterotondo Scalo, Italy) , D. Centonze ( Dipartimento di Scienze Agrarie, degli Alimenti e dell'Ambiente, Università degli Studi di Foggia, Italy) , A. Cartoni ( CNR, Istituto di Struttura della Materia, Area della Ricerca di Roma 1, Monterotondo Scalo, Italy , Dipartimento di Chimica, ‘Sapienza’ Università di Roma, Roma, Italy) , L. Avaldi ( CNR, Istituto di Struttura della Materia, Area della Ricerca di Roma 1, Monterotondo Scalo, Italy) c d f Dipartimento di Scienze Agrarie, degli Alimenti e dell'Ambiente, Università degli Studi di Foggia, Italy g Dipartimento di Chimica, ‘Sapienza’ Università di Roma, Roma, Italy
Abstract

The ElectroSpray Ionization (ESI) allows to bring intact and isolated units of large organic molecules in the gas phase. The technique uses  a solution of the molecule of interest flowing in a small capillary held at high voltage (HV, typically a few kV) with respect to a grounded counter electrode placed few cm away. The HV produces a spray of charged droplets whose size  continues to decrease by solvent evaporation and Coulombic explosion until a gas of molecular ions is formed. The ESI process usually takes place in air and then the jet can be transported into a vacuum chamber for the analysis or deposition.

A device based on an ESi source is under construction at the CNR-ISM Montelibretti. Presently, it consists of i) a heated capillary to transport the charged species in vacuum and ii) a first differential pumping stage equipped with an octupole ion guide. A vacuum chamber housing a quadrupole mass spectrometer for m/z selection of the species, followed by a quadrupolar deflector to direct them towards a deposition chamber is being designed and will soon be commissioned for ‘soft-landing’ deposition of large biomolecular species [1]. All in all, this is quite complex and costly set-up, which may suffer of severe limitations due to the low fluency of the m/z selected species. The long term goal of the project is to increase the intensity of the ESI source in a custom apparatus in order to make ‘soft landing’ a competitive technique for nanotechnology applications such as the production of biosensors and organic devices.

In parallel to the design of the in-vacuum apparatus, the potentiality of the ESI technique for the deposition of active enzymes is being tested using a set-up for ‘in-air’ deposition. This approach provides an effective removal of the solvent, the advantage to operate at ambient pressure or in controlled atmosphere, a significant reduction of costs and times of the process, the possibility to be easily automatized and a direct scale-up.

Laccase, a well-known enzyme used for the detection of polyphenols in different matrices [2,3] is used for these studies. Preliminary results showing the applicability of the ESI deposition on screen printed electrodes will be presented.

 

References

[1] D.E. Clemmer et al J. Am. Chem. Soc. 117 (1995) 10141

[2] M.M. Rodríguez-Delgado et al. Trends in Anal. Chem. 74 (2015) 21

[3] M. Verrastro et al. Talanta 154 (2016) 438