A new miniaturized multiarray biosensor system for fluorescence detection

Abstract

A miniaturized biosensor-based optical instrument has been designed and fabricated for multiarray fluorescence measurements of several biomediators in series, with applications in environmental monitoring and agrofood analysis. It is a multicell system featuring two arrays of five static cells (1 × 1 × 2 cm3) which are sealed to avoid contamination. Every cell is made up by two modular sections: the bottom compartment with optical LED light excitations and a photodiode detector for fluorescence emission capture, and the top biocompatible compartment where the biosample is deposited. The system (0.250 kg without batteries and case, 100 × 100 × 150 mm3 internal case dimensions) is equipped with electronic control boards, a flash memory card for automatic data storage, and internal batteries, thus being portable and versatile. The instrument allows one to perform simultaneous and multiparametric analyses and offers a large applicability in biosensor technology. The first prototype has been implemented with genetically modified oxygenic photosynthetic algae that were employed in the instrument experimental testing by monitoring pesticide pollution in water. Pesticides modify the photosystem II (PSII) activity in terms of fluorescence quenching. The PSII complex features a natural nanostructure and can be considered a sophisticated molecular device. Results from measurements employing several PSII mutants and six different pesticides at increasing concentrations and incubation times are presented and discussed.

Computational Biology, Protein Engineering, and Biosensor Technology: a Close Cooperation for Herbicides Monitoring

“…Minimal media were used to select photosynthetically active colonies generated after the integration of the psbA variant produced both by random and site-directed PCR (Dauvillee et al, 2004). Selected mutants were then characterised by analysing their photosynthetic performance and the sensitivity and/or resistance to different classes of herbicides assessed (Tibuzzi et al, 2007;Rea et al, 2009;Giardi et al, 2009;Scognamiglio et al, 2009). After the characterization, the best performing mutants were immobilized on screen-printed electrodes and integrated in amperometric or potentiometric circuits.…”

Photosynthetic Proteins Created by Computational and Biotechnological Approaches in Biosensing Applications

“…15.16). Multiarray biosensors Tibuzzi et al 2007a;Tibuzzi et al 2008) were used in order to investigate the response of wild-type, PSII-D1 protein mutants obtained by site-directed mutagenesis, and atrazine-resistant plants to a series of herbicides. Each cell in a multiarray biosensor (Fig.…”

Plant tissue-and photosynthesis-based biosensors

“…Two of these mutants, Ser and Lys, exhibited supersensitivity for the herbicides atrazine, diuron and phenmediphan (Johanningmeir et al, 2006). A miniaturized biosensor-based optical instrument has been designed and fabricated for multi-array fluorescence measurements of several D1 mutants of Chlamydomonas reinhardtii (Tibuzzi et al, 2007). Six pesticides were analysed: atrazine, diuron, ioxynil, terbutylazine, prometryn and linuron.…”