A Graphenic Biosensor for Real-Time Monitoring of Urea During Dialysis

A voltammetric pH sensor for food and biological matrices

“…Potentiometric sensors are usually characterized by relatively simple electronics and a working setup made of two electrodes where the working electrode is covered by a pH sensitive material or an ion selective membrane is used. This approach is the oldest and is still so widely used that many works can be found in the recent literature [43][44][45][46][47][48]. The main drawback of potentiometric sensors is the poor selectivity due to the measurement of the whole cell potential [49].…”

A graphenic and potentiometric sensor for monitoring the growth of bacterial biofilms

“…At the same time, defects provide reactive moieties such as the hydroxyl (OH) and carboxyl (COOH) groups that foster bacterial adhesion and electron transfer [51,52,53]. Furthermore, rGO can be easily functionalized to improve sensor performance in different matrices [52,53]; in this case, the functionalization with 4-aminobenzoic acid was chosen to increase the number of carboxylic groups on the electrode surface and improve the sensitivity of the device [46].…”

“…Graphene oxide (GO) reduction and functionalization were performed as previously described [46,47]. Briefly, a 4 mL GO solution 4 mg/mL (C: 49-56%; O: 42-50%, H: 0-1%; N: 0-1%; S: 2-4%) (Graphenea), was reduced with 0.3108 g (0.45M) of L-ascorbic acid (LAA, A7506) (Sigma Aldrich).…”

“…Characterization of graphene oxide reduced with L-ascorbic acid and functionalized with 4amminobenzoic acid (rGO-AB) has been described by Bonini et al [46].…”

Recent Advances in Optical, Electrochemical and Field Effect pH Sensors

“…Poma and coworkers decorated rGO with different organic molecules (4-aminobenzoic acid and 4-amino-fenilacetic acid) and improved the sensitivity up to 45 mv/pH in sea water, blood serum, and exudate [67][68][69][70]. A similar rGO-based sensor functionalized with 3-(4-aminophenil)propionic acid was efficiently transferred on paper and tested against the same matrices ( Figure 3C) [71].…”