Surface plasmon resonance based fiber optic sensor for the detection of triacylglycerides using gel entrapment technique

A novel surface plasmon resonance based fiber optic sensor for specific and sensitive estimation of triacylglycerides is reported. The sensor is based on the wavelength interrogation technique. Lipase enzyme, which is used to hydrolyse triacylglycerides into glycerol and fatty acids, is immobilized on the silver coated unclad portion of an optical fiber in a gel matrix. The fabricated sensor was tested for different concentrations of triacylglycerides. The shift in resonance wavelength of the transmission (SPR) spectra is directly proportional to the concentration of triolein/triacylglycerides. Sensor shows optimum response when operated at 37 °C and pH 7.0 with a response time 1 min and sensitivity 3.17 nm/mM. The performance of the sensor is linear in the range of 0.5–7.0 mM concentration of triacylglycerides (which is the range of triacylglycerides in human blood) and hence can be used in medical applications. The proposed sensor provides label free detection, has a fast response and high sensitivity, is compact, easy to fabricate and cost effective.