Checking for Pesticide Residues and BPA Is as Easy as Measuring Blood Sugar: IPB University Researchers Develop a Fast and Inexpensive Sensor
Pesticide residues in fruits and vegetables, as well as hazardous substances in food packaging, can now be detected using a small sensor that resembles a blood glucose meter.
This nanomaterial based electrochemical sensor was developed by IPB University researcher Prof Wulan Tri Wahyuni S to make food safety analysis fast, simple, and low cost.
She presented this innovation during her IPB University Full Professor Inaugural Lecture on Saturday (10/24), with the research title “Nanomaterial Based Electrochemical Sensors: Rapid Analysis Technology for Food Quality and Safety Assurance.”
A Sensor Half the Size of a Pen
Prof Wulan explained that an electrochemical sensor is a small device consisting of a transducer to interpret chemical reaction signals and an electrode as the measurement site.
“The electrodes can be rod-shaped, about half the size of a pen or strip shaped, like a blood glucose meter,” she said.
She added, “The substance being detected reacts with the electrode and generates an electric current whose magnitude is proportional to its concentration. To enhance sensitivity and selectivity, the electrodes are modified with nanomaterials.”
Pesticide Residues in Fruits and Vegetables
A sensor has been developed to detect paraoxon-ethyl and carbaryl, two pesticides used by farmers in Indonesia. If ingested, both can pose health risks.
For paraoxon-ethyl, a sensor based on multi-walled carbon nanotubes (MWCNT) and graphene is capable of detecting concentrations well below the maximum residue limit (0,05 milligrams per kilogram).
“Tests on cabbage and green apples showed results that were not significantly different from those obtained using spectrophotometry,” she explained.
For carbaryl, Prof Wulan used rod-shaped gold nanoparticles. Nanoparticles with the lowest length to width ratio produced the lowest detection limit. The sensor was applied to cabbage, Chinese cabbage, and cucumbers.
“We have also developed strip-shaped electrodes with a detection limit lower than the maximum residue limit for carbaryl, making them suitable for direct use in the field,” she said.
BPA from Baby Bottles
Sensors made from nanomaterial composites are also used to detect bisphenol A (BPA), a compound that can leach from certain plastic packaging, such as baby bottles, baby feeding utensils, and teething toys.
“The sensor successfully detected BPA migrating from milk bottles, with a detection limit well below the permitted migration limit. Once again, the results showed no significant difference compared to spectrophotometry,” explained Prof Wulan.
Detecting Clove Adulteration
In addition to hazardous substances, this sensor was developed to detect spice adulteration. The sensor records the fingerprint or unique signal pattern of samples with complex compositions, and one of its applications is detecting adulteration in ground cloves.
Looking ahead, Prof Wulan aims to focus sensor development on miniaturization and automation. (dh) (IAAS/LAN)
