Miniaturized fiber-optic biosensor to monitor asparagine in clinical samples

Asparagine biosensor was constructed by co-immobilized anti-leukemic enzyme (L-asparaginase) and absorptive pH sensitive indicator on to plastic chips of 5mm through hydro sol-gel approach. Asparagine is used as a biomarker for detection of acute lymphoblastic leukemia. In this research work asparagine biosensor was developed focusing on L-asparaginase activity as bioassay principle. L-asparagine gets hydrolyzed into L-aspartic acid and ammonia by enzyme L-asparaginases, thereby concentration of ammonia produced was monitored by miniaturized fiber-optic spectrophotometer. Anti-leukemic enzyme L-asparaginase used in the present research work was screened from Staphylococcus sp. isolated from sewage waste water. Fiber optic approach was used for substrate analysis using transparent chips; sample volume up to 5μl was used for sample study and absorption spectrum was observed. Developed biosensor was applied to clinical samples from the patients of different ages (Throat, blood cancer) to monitor asparagine concentration. Fiber optic based biosensor proved to be suitable approach for substrate breakdown with miniaturized level up to 5μl and detection limit of 0.1nM