Construction of an amperometric TG biosensor based on AuPPy nanocomposite and poly (indole-5-carboxylic acid) modified Au electrode.
A method is described for construction of an amperometric triglyceride (TG) biosensor based on covalent co-immobilization of lipase, glycerol kinase and glycerol-3-phosphate oxidase onto gold polypyrrole nanocomposite decorated poly indole-5-carboxylic acid electrodeposited on the surface of a gold electrode. The enzyme electrode was characterized by transmission electron microscopy, scanning electron microscopy, electrochemical impedance studies, Fourier transform infrared spectroscopy and cyclic voltammetry. Biosensor showed optimum response within 4 s at pH 6.5 and 35 °C, when polarized at +0.1 V against Ag/AgCl. There was a linear relationship between sensor response and triolein concentration in the range 50-700 mg/dl. Biosensor was employed for determination of TG in serum. Detection limit of the biosensor was 20 mg/dl. Biosensor was evaluated with 91-95 % recovery of added triolein in sera and 4.14 and 5.85 % within and between batch coefficients of variation, respectively. There was a good correlation (r = 0.99) between sera TG values by standard method (Enzymic colorimetric) and the present method. The biosensor was unaffected by a number of serum substances at their physiological concentration. Biosensor lost 50 % of its initial activity after its 100 uses over 7 months, when stored at 4 °C.
Department of Biochemistry, M. D. University, Rohtak 124 001, Haryana, India.
Jagriti
J
Narang
Nidhi
N
Chauhan
Poonam
P
Rani
C S
CS
Pundir
D000328:Adult; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D001774:Blood Chemical Analysis / Q000295:instrumentation / Q000379:methods; D058266:Dielectric Spectroscopy; D004800:Enzymes, Immobilized; D005991:Glycerol Kinase; D005993:Glycerolphosphate Dehydrogenase; D006046:Gold; D006801:Humans; D007211:Indoles; D008049:Lipase; D053768:Metal Nanoparticles / Q000737:chemistry / Q000648:ultrastructure; D008854:Microscopy, Electron; D053761:Nanocomposites / Q000737:chemistry / Q000648:ultrastructure; D011108:Polymers; D011758:Pyrroles; D017550:Spectroscopy, Fourier Transform Infrared; D014280:Triglycerides / Q000097:blood*
D004800:Enzymes, Immobilized; D007211:Indoles; D011108:Polymers; D011758:Pyrroles; D014280:Triglycerides; C514680:poly(indole-5-carboxylic acid); C067635:polypyrrole; D006046:Gold; D005993:Glycerolphosphate Dehydrogenase; C098831:glycerol-3-phosphate oxidase; D005991:Glycerol Kinase; D008049:Lipase