Acetylcholinesterase immobilised eggshell membrane-based optical biosensor for organophosphate detection

Abstract

The development of an optical biosensor for the determination of malathion based on acetylcholinesterase (AChE) inhibition using Ellman’s reagent is reported. The AChE has been immobilised onto the eggshell membrane (ESM) using glutaraldehyde as a cross-linking agent. Scanning Electron Microscopic (SEM) studies and Fourier Transformed Infra-Red (FTIR) characterisations have been carried out to affirm the successful immobilisation of AChE onto the ESM. Under optimum conditions, the developed biosensor estimated the pesticide concentration in the range of 0.1–50 ng/mL with a limit of detection (LOD) of 0.1 ng/mL within 30 min. Parameters affecting the biosensor response such as concentration of enzyme, substrate and inhibition time were optimised. The stability and reusability of the AChE/ESM sensor have been observed as 31 days at 4°C and two times, respectively.

Keywords:

• acetylcholinesterase
• eggshell membrane
• glutaraldehyde
• Ellman’s reagent
• optical biosensor

Acknowledgement

We are thankful to Central Instrument Laboratory (CIL) facility of Panjab University (PU), Chandigarh, for SEM studies.

Additional information

Funding

Financial support received under University Grants Commission (UGC) – Start Up Grant and University Grants Commission Basic Scientific Research Fellowship (UGC-BSRF), Department of Biotechnology (DBT) sponsored project no. BT/PR5503/MED/29/642/2012 and Promotion of University Research and Scientific Excellence Programme of Department of Science and Technology (DST-Purse II) is acknowledged.