Prussian Blue based screen printed biosensors with improved characteristics of long-term lifetime and pH stability

Abstract

The promising advantages of Prussian Blue (PB) as catalyst and of the thick film screen printing technology have been combined to assemble sensors with improved characteristics for the amperometric determination of H 2 O 2 . PB-modified screen printed electrodes were applied to detect H 2 O 2 at an applied potential of (/0.05 V versus the internal screen printed Ag pseudoreference electrode, showing a detection limit of 10 (7 mol l (1 , a linearity range from 10 (7 to 5 )/10 (5 mol l (1 , a sensitivity of 234 mA mmol l (1 cm (2 , and a high selectivity. Improved stability at alkaline pH values was also observed, which made possible their use with enzymes having an optimum basic pH. Then, the immobilisation of a single enzyme (glucose oxidase (GOD) or choline oxidase (ChOX)) or of two enzymes, acetylcholinesterase (AchE) coimmobilised with ChOX, has been performed on the surface of PB modified screen-printed electrodes (SPEs) using glutaraldehyde and Nafion † . ChOX has been selected as an example of enzyme working at alkaline pH. The choline biosensors showed a detection limit of 5 )/10 (7 mol l (1 , a wide linearity range (5 )/10 (7 Á/ 10 (4 mol l (1 ), a high selectivity and a remarkable long term stability of 9 months at 4 8C, and at least 4 weeks at room temperature. Similar analytical characteristics and stability were observed with the acetylcholine biosensors. #

Real time monitoring of alcoholic fermentation with low-cost amperometric biosensors

“…The SPEs were pre-treated in TPi + KCl, by applying an anodic potential of 1.7 V for 180 s. They were then stored dry at room temperature (RT) in the dark prior to use (Ricci, Amine, Palleschi, & Moscone, 2003).…”

“…According to the procedure of Ricci et al (2003), PB modifica- tion was left on the electrode surface for 10 min and then rinsed with a few milliliters of 10 mM HCl. The electrodes were then left 90 min in the oven at 100°C to obtain a more stable and active layer of PB.…”

Development of a recombinant Fab-fragment based electrochemical immunosensor for deoxynivalenol detection in food samples

“…A strip of eight screen-printed electrodes was connected to the potentiostat by an 8-channel multiplexer. Before use, ScPEs were pre-treated in 0.01 M PBS buffer pH 7.4 by applying an anodic potential of 1.7 V for 180 s (a procedure which improves the sensitivity and reproducibility of these electrodes (Ricci et al, 2003)) and kept dried in the dark until ready to use (Ricci et al, 2003).…”

Prussian Blue Modified Carbon Nanotube Paste Electrodes: A Comparative Study and a Biochemical Application

“…[15][16][17][18]27,28] The modification of an electrode surface with a layer of PB makes in fact it possible to measure H 2 O 2 at low applied potential (around 0.0 V) and to greatly decrease any electrochemical interference, as demonstrated in a previous article. [19] In this work, we report for the first time the modification of single walled carbon nanotube powder with Prussian Blue and the successive assembling of composite electrode for H 2 O 2 detection. The electrochemical behavior of these probes has been fully characterized by cyclic voltammetry in terms of surface charge, peak currents, formal potential, and ÁEp.…”