Synthesis of one-dimensional gold nanostructures and the electrochemical application of the nanohybrid containing functionalized graphene oxide for cholesterol biosensing.
This manuscript reports a new approach for the synthesis of one dimensional gold nanostructure (AuNs) and its application in the development of cholesterol biosensor. Au nanostructures have been synthesized by exploiting β-diphenylalanine (β-FF) as an sacrificial template, whereas the Au nanoparticles (AuNPs) were synthesized by ultrasound irradiation. X-ray diffractometer (XRD), scanning electron microscope (SEM) and energy dispersive analysis of X-rays (EDAX) have been employed to characterize the morphology and composition of the prepared samples. With the aim to develop a highly sensitive cholesterol biosensor, cholesterol oxidase (ChOx) was immobilized on AuNs which were appended on the graphite (Gr) electrode via chemisorption onto thiol-functionalized graphene oxide (GO-SH). This Gr/GO-SH/AuNs/ChOx biosensor has been characterized using cyclic voltammetry (CV), electrochemical impedance spectroscopy and chronoamperometry. CV results indicated a direct electron transfer between the enzyme and the electrode surface. A new potentiostat intermitant titration technique (PITT) has been studied to determine the diffusion coefficient and maxima potential value. The proposed biosensor showed rapid response, high sensitivity, wide linear range and low detection limit. Furthermore, our AuNs modified electrode showed excellent selectivity, repeatability, reproducibility and long term stability. The proposed electrode has also been used successfully to determine cholesterol in serum samples.
Department of Chemistry and Research Centre, N.M.K.R.V. College for Women, Jayanagar, Bangalore 560 011, India; Department of PG Studies and Research in Biochemistry, Jnana Sahyadri, Kuvempu University, Shankaraghatta, Shimoga 577451, India.
Seetharamaiah
S
Nandini
Department of Chemistry and Research Centre, N.M.K.R.V. College for Women, Jayanagar, Bangalore 560 011, India; Department of PG Studies and Research in Biochemistry, Jnana Sahyadri, Kuvempu University, Shankaraghatta, Shimoga 577451, India.
Seetharamaiah
S
Nalini
School of Chemistry, Reva University, Kattigenahalli, Yelahanka, Bangalore 560064, India.
M B Madhusudana
MB
Reddy
Department of Chemistry and Research Centre, N.M.K.R.V. College for Women, Jayanagar, Bangalore 560 011, India. Electronic address: sureshssmrv@yahoo.co.in.
Gurukar Shivappa
GS
Suresh
Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai 400 085, India. Electronic address: jsmelo@barc.gov.in.
Jose Savio
JS
Melo
Department of PG Studies and Research in Biochemistry, Jnana Sahyadri, Kuvempu University, Shankaraghatta, Shimoga 577451, India. Electronic address: bpniru@gmail.com.
Pathappa
P
Niranjana
Department of Energy Systems and Engineering, Daegu Gyeongbuk Institute of Science and Technology, Daegu 711-873, Republic of Korea.
Jakkid
J
Sanetuntikul
Department of Energy Systems and Engineering, Daegu Gyeongbuk Institute of Science and Technology, Daegu 711-873, Republic of Korea.
Sangaraju
S
Shanmugam
D015374:Biosensing Techniques / Q000379:methods*; D060326:Chemistry Techniques, Synthetic; D002784:Cholesterol / Q000032:analysis*; D002789:Cholesterol Oxidase / Q000737:chemistry / Q000378:metabolism; D004563:Electrochemistry; D004566:Electrodes; D005292:Ferricyanides / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D053768:Metal Nanoparticles / Q000737:chemistry*; D036103:Nanotechnology; D010087:Oxides / Q000737:chemistry*; D013696:Temperature
D005292:Ferricyanides; D010087:Oxides; D006046:Gold; D006108:Graphite; D002784:Cholesterol; D002789:Cholesterol Oxidase; C028033:potassium ferricyanide
Cholesterol; Electrochemical biosensor; Functionalized graphene oxide; Gold nanostrucutres; Peptide nanotubes; β-diphenylalanine