Paracetamol sensors

Fig. 12. Response of the MIP sensor to phenacetin (curve 1), paracetamol (curve 2), antifebrin (curve 3), phenetol (curve 4). The same electrode was used for all detections in a 10-ml sample volume (aqueous system). MIP was composed of MAA and EGDMA and imprinted with phenacetin. Reprinted with permission from Tan Y, Peng H, Liang C, Yao S (2001) Sensors Actuators B 73 179. Copyright 2001 Elsevier Science...

An early example of an MIP-QCM sensor was a glucose monitoring system by Malitesta et al. (1999). A glucose imprinted poly(o-phenylenediamine) polymer was electrosynthesized on the sensor surface. This QCM sensor showed selectivity for glucose over other compounds such as ascorbic acid, paracetamol, cysteine, and fructose at physiologically relevant millimolar concentrations. A unique QCM sensor for detection of yeast was reported by Dickert and coworkers (Dickert et al. 2001 Dickert and Hayden 2002). Yeast cells were imprinted in a sol-gel matrix on the surface of the transducer. The MIP-coated sensor was able to measure yeast cell concentrations in situ and in complex media. A QCM sensor coated with a thin permeable MIP film was developed for the determination of L-menthol in the liquid phase (Percival et al. 2001). The MIP-QCM sensor displayed good selectivity and good sensitivity with a detection limit of 200 ppb (Fig. 15.7). The sensor also displayed excellent enantioselectivity and was able to easily differentiate the l- and D-enantiomers of menthol. 

How analytical methods deal with interferences is one of the more ad hoc aspects of method validation. There is a variety of approaches to studying interference, from adding arbitrary amounts of a single interferent in the absence of the analyte to establish the response of the instrument to that species, to multivariate methods in which several interferents are added in a statistical protocol to reveal both main and interaction effects. The first question that needs to be answered is to what extent interferences are expected and how likely they are to affect the measurement. In testing blood for glucose by an enzyme electrode, other electroactive species that may be present are ascorbic acid (vitamin C), uric acid, and paracetamol (if this drug has been taken). However, electroactive metals (e.g., copper and silver) are unlikely to be present in blood in great quantities. Potentiometric membrane electrode sensors (ion selective electrodes), of which the pH electrode is the... 

Selectivity of the MIP-PZ sensors can be improved by separately optimizing the binding and determination medium. MIPs combined with PZ transducers are unique in selectivity with respect to enantiomers. The proper choice of functional monomers used for imprinting can improve this selectivity at a very low LOD. For instance, paracetamol has been determined with the MIP-QCM chemosensor using VPD and MAA as the MIP functional monomers [109], Affinity of this... 

The same kind of glucagon-insulin test is also used for longer-term experiments. The results of the first series of tests (n = 15) showed that, when periodically calibrated, 90% of implanted sensors followed correctly the blood glycaemia changes for three days and 35% up to seven days. The problem of various interferences, especially that of paracetamol, is now under investigation. 

Due to their small size and high surface area, nanoparticles can be applied to modify electrode surface property. Convenient and sensitive electrochemical sensors to various targets have been set up by using nanoparticle modification. The determination of acetaminophen in a commercial paracetamol oral solution was reported using a multiwall CNTs composite film-modified glassy carbon electrode with a detection limit of 50 nM (Li etal. 2006a). Heavy metal ions, such as ar-senite (Dai and Compton 2006 Majid et al. 2006) and lead ion (Cui et al. 2005),... 

Tan Y, Zhou Z, Wang P, Nie L, and Yao S. A study of a biomimetic recognition material for the BAW sensor by molecular imprinting and its application for the determination of paracetamol in the human serum and urine. Talanta 2001 55 337-347. 

Electric company (Osawa et al., 1981). The membrane developed by Newman (1976) is being used in the 23 A glucose analyzer (Yellow Springs Instrument Co., USA, see Section 5.2.3). Lindh et al. (1982) showed that the cellulose acetate membrane is not truly selective for H2O2, but only decreases the permeation of larger molecules. The sensor was 3 times more sensitive to the glycolysis inhibitor paracetamol than to glucose. The membrane permeability was shown to depend on membrane age. 

The oxygen electrode according to Clark [9] and its version modified for H2O2 indication [10] are the most widely used transducers in biosensors. The electrode potential is crucial for the selectivity of the sensor. Any electroactive substance being converted at lower potential contributes to the total current. Thus at an electrode potential of -1-600 mV for H2O2 measurement, ascorbic acid, uric acid, or paracetamol are oxidized as well. 

Glucose-imprinted poly(o-phenylenediamine) was electrosynthe-sized on the electrode of a QCM [9]. The linear range was up to 20 mM and the response was saturated at around 100 mM. Ascorbic acid, paracetamol and cystein, which are common interferences in practical use, showed no appreciable response however, the sensor responded slightly to fructose. 

Electrochemical Sensor Combined with Molecular Imprinted Polymer for Paracetamol Determination... 

Peng and co-authors developed a new electrochemical sensor combining a molecularly imprinted technique and an electropolymerization method. A molecularly imprinted polymer film was fabricated by electropolymerizing o-phenylenediamine in the presence of paracetamol after depositing carboxyl-functionalized multiwalled... 

Y. Peng, Z. Wu, and Z. Liu, An electrochemical sensor for paracetamol based on an elec-tropolymerized molecularly imprinted o-phenylenediamine film on a multi-walled carbon nanotube modified glassy carbon electrode. Anal. Methods, 6, 5673-5681, 2014. 

Ruiz-Medina, A., M. L. Fernandez-de Cordova, M. J. Ayora-Canada, M. I. Pascual-Reguera, and A. Molina-DLaz. 2000. A flow-through solid phase UV spectrophotometric biparameter sensor for the sequential determination of ascorbic acid and paracetamol. Anal. Chim. Acta 404 131-139. 

N.F. Atta, M.F. El-Kady, A. Galal, Palladium nanoclusters-coated polyfuran as a novel sensor for catecholamine neurotransmitters and paracetamol. Sens. Actuators, B 141 (2009) 566-574. 

Ozcan L, ahin Y (2007) Determination of paracetamol based on electropolymerized-molecularly imprinted polypyrrole modified pencil graphite electrode. Sensor Actuat B 127 362-369... 

Fig. 13.9 Discrimination of standard solutions containing caffeine, paracetamol, or acetylsalicylic acid using a LDA model based on a subset of E-tongue sensors, selected by the SA variable selection algorithm.

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