SENSITIVE DETERMINATION OF 3,4-DIHYDROXY-L-PHENYLALANINE BY A CLOUD FUNNEL MUSHROOM (Clitocybe nebularis (Batsch), P. Kumm.) HOMOGENATE-BASED AMPEROMETRIC BIOSENSOR

Abstract

3,4-dihydroxy-L-phenylalanine (L-DOPA) is one of the precursor molecules for the biosynthesis of neurotransmitters in the brain. Monitoring of L-DOPA levels as a drug or biomolecule in biological fluids is crucial for the treatment of patients suffering from Parkinson’s Disease. This study aimed to construct a cloud funnel mushroom (Clitocybe nebularis (Batsch), P. Kumm.) tissue homogenate-based biosensor for precise and sensitive detection of L-DOPA in artificial plasma and urine. For this purpose, in the fabrication of the biosensor, tissue homogenate of C. nebularis was immobilized into a carbon paste electrode by using graphite, mineral oil, gelatine and glutaraldehyde. The amperometric signals corresponding to 600 s were recorded as response current for each L-DOPA concentration. All amperometric measurements were carried out at ⁻700 mV (versus Ag|AgCl). The present biosensor successfully detected L-DOPA with a linear dynamic range at 2.5-100 µM and Limit of Detection (LOD) value as 0.76 µM, as well as standard deviation as ±0.41 µM and coefficient of variation as 0.82% (n=16). Additionally, the determination of L-DOPA spiked in artificial plasma and urine was carried out successfully. The present work would be the first study that utilized C. nebularis tissue as a biosensor component.

Keywords

• clitocybe nebularis
• l-dopa
• carbon-paste electrode
• tissue homogenate
• electrochemistry