Gold nanoparticle mediated designing of non-hydrolytic sol-gel cross-linked metformin imprinted polymer network: a theoretical and experimental study.
A sensitive and selective electrochemical sensor based on molecularly imprinted polymers was developed for trace level detection of metformin-an antidiabetic drug. For the first time, we have applied non-hydrolytic sol-gel matrix as a cross-linking agent in the field of molecular imprinting. To create the sol-gel matrix and enhance the electro-conductivity of the proposed sensor citrate-capped gold nanoparticle were used. The morphologies and properties of the sensor were characterized by scanning electron microscopy, cyclic voltammetry, electron impedance spectroscopy, chronocoulometry and differential pulse voltammetry. Energy of the HOMO and LUMO orbitals and Mülliken's atomic charges of template molecule were also calculated using density functional theory utilizing B3LYP with 3-21G-basis set. The theoretical results allied to the diagnostic criteria of the cyclic voltammetry indicate that the metformin redox mechanism is associated to the irreversible oxidation process of metformin-imino-group to N-hydroxyimino-group. The results demonstrated that the prepared sensor had excellent selectivity and high sensitivity for metformin in the linear range from 0.02 to 80 ng ml(-1) with a detection limit of 0.005 ng ml(-1) (S/N=3). The sensor was also successfully employed to detect metformin in pharmaceutical sample.
Department of Applied Chemistry, Indian School of Mines, Dhanbad, Jharkhand 826004, India.
Ekta
E
Roy
Department of Applied Chemistry, Indian School of Mines, Dhanbad, Jharkhand 826004, India.
Santanu
S
Patra
Department of Applied Chemistry, Indian School of Mines, Dhanbad, Jharkhand 826004, India. Electronic address: rshmmadhuri@gmail.com.
Rashmi
R
Madhuri
Functional Nanomaterials Research Laboratory, Department of Applied Physics, Indian School of Mines, Dhanbad, Jharkhand 826004, India.
Prashant K
PK
Sharma
D015374:Biosensing Techniques / Q000379:methods; D055664:Electrochemical Techniques / Q000379:methods*; D006046:Gold / Q000737:chemistry*; D007004:Hypoglycemic Agents / Q000032:analysis*; D057230:Limit of Detection; D008687:Metformin / Q000032:analysis*; D008958:Models, Molecular; D054802:Molecular Imprinting / Q000379:methods*; D053758:Nanoparticles / Q000737:chemistry; D044367:Phase Transition; D011108:Polymers / Q000737:chemistry*
D007004:Hypoglycemic Agents; D011108:Polymers; D006046:Gold; D008687:Metformin
Electrochemical sensor; Gold nanoparticles; Metformin; Molecular imprinted polymer; Non-hydrolytic sol–gel