The present invention provides a swept source interrogation setup for a gold-coated tilted fiber Bragg grating sensor. A laser ring that has a sweeping laser wavelength is used instead of a spectrum analyser. The laser ring is controlled by a narrowband fiber Bragg grating mounted on a piezoceramic transducer. The sweeping laser wavelength covers the range of sensitivity of surface plasmon resonance of the gold-coated tilted fiber Bragg grating. The gold coat is functionalised with L-cysteine ligand. The gold-coated tilted fiber Bragg grating is exposed to liquid analyte that contains metal ions. A change in spectrum by the sweeping laser is captured by a photodetector and monitored by a microcontroller.