Prototype instrument development for non-destructive detection of pesticide residue in apple surface using Raman technology

•Optical instrument was developed for pesticide residue detection in apple surface.•Hardware and software system was self developed as prototype instrument.•The instrument can detect chlorpyrifos pesticide in apple surface nondestructively.•6.69 mg/kg of pesticide residue in apple surface is detectable by the instrument.•The system can detect the pesticide residue in apple surface within 4 s.

Apple is one of the highly consumed fruit and also a major source of pesticide carrier to human health. This study explores the application of Raman spectroscopy for detection of commercially available organophosphorus (chlorpyrifos) pesticide in apple surface. Optical instrument prototype equipped with Raman spectroscopy system with 785 nm laser excitation source was developed for non-destructive, rapid and accurate detection of pesticide residue in apple surface, overcoming the loopholes of traditional detection methods. Software was self developed to control the functionality of Raman CCD, acquire and process the Raman spectral data and display result in real time. The samples detected by the developed system were tested in High Performance Liquid Chromatography. The result shows that the developed system can detect chlorpyrifos residue to minimum limit of 6.69 mg/kg in apple surface within less than 4 s. This innovative and promising system can be a breakthrough technology for pesticide detection in fruits and vegetables.