Image created by Dr. Michael J. Miller
Researchers at the University of Social Welfare and Rehabilitation Sciences in Tehran have successfully designed an ultra-sensitive colorimetric nanobiosensor capable of providing rapid, visual detection of microbial growth on medical surfaces and equipment. The technology aims to streamline the monitoring of microbial contamination and significantly reduce hospital-acquired infections (HAIs).
The presence and proliferation of pathogenic microorganisms in healthcare facilities, food processing plants, restaurants, and other sensitive environments pose severe public health risks. Consequently, timely identification of microbial loads on surfaces and equipment—enabling prompt disinfection—remains one of the most critical strategies for preventing pathogen transmission.
Hospital-acquired infections represent a major challenge for healthcare systems globally. These infections, which are not present at the time of patient admission and develop after several days of hospitalization, lead to extended hospital stays, increased treatment costs, prolonged patient disability, and secondary complications.
A primary vector for HAIs is the contamination of medical surfaces and equipment. Current assessment methods rely heavily on microbial culturing—a process that is time-consuming, expensive, and requires specialized laboratory equipment and technical expertise for interpretation.
To address these limitations, the research team developed an ultra-sensitive colorimetric nanobiosensor to quantify microbial loads on surfaces. Constructed from an electrospun pad and a specialized indicator polymer, the sensor operates by undergoing a visible color change when exposed to varying levels of microbial contamination.
Under this protocol, the thin sensor pad is applied directly to a surface suspected of contamination. Initially a faint light blue, the pad gradually shifts along a color spectrum toward red in the presence of microbial activity. This transition is easily viewed through a transparent protective cover on the pad.
The color spectrum generated by the sensor was calibrated and standardized under laboratory conditions, providing users with printed reference charts. Without requiring complex equipment, personnel can simply observe the sensor's color shift after a few hours to a few days—depending on the level of contamination—and compare it against the standard chart to estimate the microbial load and determine whether immediate disinfection is required.
By making microbial monitoring simpler, faster, and more cost-effective, this technology offers a practical tool for infection control in hospitals, clinical centers, food industries, laboratories, and other high-risk environments.
Infection control remains a critical priority in healthcare settings, where dedicated "Infection Control Units" operate under hospital leadership and nursing management. These units coordinate health protocols, report to infection control committees, and enforce approved guidelines alongside infection control physicians and clinical microbiologists.
The project was led by Dr. Seyed Mohammad Ali Hosseini, Associate Professor at the University of Social Welfare and Rehabilitation Sciences in Tehran and Knowledge Translation Fellow in Cardiac Rehabilitation at the University of Technology Sydney (UTS), Australia. Mohammad Ekerami, a PhD candidate in Food Industry at the University of Tehran, served as a member of the R&D team, while Ali Ekerami, a Master's student in Community Health Nursing at the University of Social Welfare and Rehabilitation Sciences, contributed to the project's execution.