title: Novel paper-based cholesterol biosensor using graphene/polyvinylpyrrolidone/polyaniline nanocomposite.
abstract: A novel nanocomposite of graphene (G), polyvinylpyrrolidone (PVP) and polyaniline (PANI) has been successfully prepared and used for the modification of paper-based biosensors via electrospraying. The droplet-like nanostructures of G/PVP/PANI-modified electrodes are obtained with an average size of 160 ± 1.02 nm. Interestingly, the presence of small amount of PVP (2 mg mL(-1)) in the nanocomposites can substantially improve the dispersibility of G and increase the electrochemical conductivity of electrodes, leading to enhanced sensitivity of the biosensor. The well-defined cyclic voltammogram of standard ferri/ferrocyanide is achieved on a G/PVP/PANI-modified electrode with a 3-fold increase in the current signal compared to an unmodified electrode. This modified electrode also exhibits excellent electrocatalytic activity towards the oxidation of hydrogen peroxide (H2O2). Furthermore, cholesterol oxidase (ChOx) is attached to G/PVP/PANI-modified electrode for the amperometric determination of cholesterol. Under optimum conditions, a linear range of 50 μM to 10mM is achieved and the limit of detection is found to be 1 μM for cholesterol. Finally, the proposed system can be applied for the determination of cholesterol in a complex biological fluid (i.e. human serum).
authors.affiliation: Program in Macromolecular Science, Faculty of Science, Chulalongkorn University, Phayathai Road, Patumwan, Bangkok 10330, Thailand.
authors.forename: Nipapan
authors.initials: N
authors.lastname: Ruecha
authors.forename: Ratthapol
authors.initials: R
authors.lastname: Rangkupan
authors.forename: Nadnudda
authors.initials: N
authors.lastname: Rodthongkum
authors.forename: Orawon
authors.initials: O
authors.lastname: Chailapakul
mesh_terms: D000814:Aniline Compounds / Q000737:chemistry; D015374:Biosensing Techniques / Q000379:methods*; D002784:Cholesterol / Q000097:blood / Q000302:isolation & purification*; D002789:Cholesterol Oxidase / Q000737:chemistry*; D004800:Enzymes, Immobilized / Q000737:chemistry; D006108:Graphite / Q000737:chemistry*; D006801:Humans; D006861:Hydrogen Peroxide; D053761:Nanocomposites / Q000737:chemistry; D010209:Paper; D011205:Povidone / Q000737:chemistry
chemical_list: D000814:Aniline Compounds; D004800:Enzymes, Immobilized; C416807:polyaniline; D006108:Graphite; D002784:Cholesterol; D006861:Hydrogen Peroxide; D002789:Cholesterol Oxidase; D011205:Povidone
keywords: Cholesterol; Graphene; Nanocomposite; Paper-based biosensor; Polyaniline; Polyvinylpyrrolidone