BOYSCAST Fellowship for the year 2007-08 by Department of Science and Technology, New Delhi to pursue research in the area of Chemical Sciences - Novel Materials & Bio Sensors for a period of twelve months at the Department of Materials Science, The Angstrom Laboratory, Uppsala University, Uppsala, Sweden.

On-chip depletory electrodes (Lab-on-a-chip) has been fabricated (based on the trials) on a silicon chip by photolithographic technique and it has been characterized for its electrochemical collection and depletion efficiency. These devices found importance in the case of reductive detection of the analytes, where the signal detection is hampered by the presence of oxygen, metal ions and other electrochemical reductive species. It is straight forward that one can easily eliminate the interfering species at the diffusion layer without much interference from the bulk species in an ‘on-chip’ microelectrode configuration under controlled flow environment.

In the case of pre-concentrative analytical detection, it is convenient that the analyte transport is self-driven rather than those subject to addition of phase transfer agents and modification of lipophilicity/lipophobicity using derivatizing agents. This concept has been exploited for the phase transfer assisted electrochemical sensing of ‘phenolic compounds’ triggered by thermodynamic factors (pH change) [Electroanalysis, 2009]. These demonstrative experiments facilitate the development of microfluidic platform to a controlled transfer of molecules for its separation and detection with improved selective and sensitive detection of analyte molecules.

Pt microelectrode has been modified with conducting polymer single walled carbon nanotube composite material and its utility for the development biosensor matrix for the selective and sensitive detection of 3,4-dihydroxy-L-phenylalaine (L-dopa) [Electroanalysis, 2009] and 3,4-dihydroxyphenethylamine (dopamine) has been attempted. The results indicated that the modified electrode facilitated determination with good sensitivity and reproducibility compared to the bare microelectrode. It is also interesting to note that the modified microelectrode could be used for the in-vivo detection and determination of selected neurotransmitter analyte in the nanomolar range with good reproducibility and little fouling effects.