Mashhad Researches Successfully Designed Blood Antibiotic-Detecting Sensors

Researches in Mashhad University of Medical Sciences have successfully designed a laboratory sensor, by which minor amounts of an antibiotic can be detected in blood.

According to WEBDA, an antibiotic is a product or substance obtained from a microorganism and destroys other microorganisms or prevents their development. Kanamycin is a widely-used antibiotic used to treat some infections in humans and animals. High doses of this medicine can cause severe side effects such as hearing and renal toxicity. Therefore, in order to prevent side effects, determining blood levels of the drug seems necessary. Several methods have already been introduced to identify and measure this drug.

Dr. Khalil Abnus, faculty member of Mashhad University of Medical Sciences and executive director of the project, emphasizing the disadvantages of the conventional methods of detecting and determining the concentration of Kanamycin, explained the aim of this project: “Generally, conventional methods used to detect Kanamycin are time-consuming and expensive. In addition, expertise is required for using the equipment.”

Associate professor of Mashhad University of Medical Sciences added: “Therefore, producing an accurate and quick fluorescence sensor to detect small amounts of the drug in the blood and milk has been studied in this research.”

According to this researcher, the designed sensor, optimized by gold nanoparticles, can detect and measure the presence and amount of "Kanamycin" with high sensitivity and selectivity; Also, the detection speed by this sensor is higher than that of similar detection methods.

Dr. Abnus explained that a molecule is excited when given energy by light, and tends to return to its steady state. He added: “This molecule emits light when returning to its steady state, which is known as fluorescence.”

According to Dr. Abnus, in this study, a fluorescence sensor has been designed based on the “aptamer”, “exonuclease III enzyme”, and gold nanoparticles, detecting very low concentrations of Kanamycin in blood serum and milk.

Regarding the stages of the project and the evaluation of the sensor, Dr. Abnus said:” The sensor was theoretically designed, then synthesized gold nanoparticles and materials were used and optimized. Labeled conjugated gold nanoparticles-complementary strands were prepared afterwards, and the detection limit and selectivity were assessed.”

He added: “This sensor is able to detect Kanamycin in the blood serum with a detection limit of 569 pM, and in milk with a detection limit of 476 pM, with high selectivity. This sensor can be used in medicine and veterinary to quantitatively measure an antibiotic drug in blood serum and milk.”

This research is conducted by Dr. Khalil Abnus, Dr. Seyed Mohammad Taghdisi Heydarian, Dr. Mohammad Ramazani, faculty members of Mashhad University of Medical Sciences, and Nour Mohammad Danesh and Perry Levi, PhD students of this university. The results of this study have been published in Journal of Sensors and Actuators B: Chemical (volume 222, 2016, pages 1-7).