Exploring the Effectiveness of Hydrophobic Glass Surface on Touch-Enabled Digital Device to Reduce Microbial Adhesion and Propagation

ABSTRACT

This study investigates the effectiveness of hydrophobic glass surfaces in reducing microbial populations on touch-enabled digital devices. Hydrophobic coatings have been proposed as a potential solution to minimize microbial adhesion and growth on device surfaces. Here, we intended to investigate the effect of hydrophobic spray on microbial load. The results were quantitatively analyzed using microbiological techniques. the nonhydrophobic surface harbors gradual microbial buildup upon time, such as threefold increase from 2 to 4 h and fivefold increase to 6 h post initial sampling with 143.6 ± 33.89 cfu/ml increase up to 264.7 ± 28.53 cfu/ml, whereas the hydrophobic surface had an overall build-up from 16.6 ± 1.2 to 50.45 ± 11.12 cfu/ml with P < 0.0001 significance. This research provides valuable insights into the potential application of hydrophobic glass coatings to mitigate microbial contamination on touch-enabled digital devices, enhancing their hygienic properties and minimizing the risk of infectious disease transmission.

INTRODUCTION

In recent years, touch-enabled digital interface devices such as smartphones, tablets, and interactive touch displays added more value proportion to the medical industry. These devices are used extensively for appointment fixing, demographic details, registration, clinical data entry, report generation, imaging, and also in public spaces such as schools, hospitals, and offices. While these devices offer convenience and connectivity, they also pose a potential risk of microbial contamination and the transmission of infectious diseases.[1,2] Microorganisms are ubiquitous in nature and are able to adhere to any surfaces, including the screens of touch-enabled digital devices. A wide variety of pathogenic microorganisms which includes Methicillin-resistant Staphylococcus aureus, Escherichia coli, fungal, and viral pathogens harbor on the mobile phones used in a clinical setting. With repeated touching and handling, these microorganisms can multiply and persist on device surfaces, posing a risk of cross-contamination.[1]

Various strategies were explored to reduce microbial populations on touch-enabled digital devices. One such approach involves the use of hydrophobic glass surfaces as the hydrophobic coatings are designed to repel water and other liquids, thereby minimizing the microbial contact and adhesion to the surface.[3,4] The effectiveness of hydrophobic glass surfaces in controlling microbial populations on touch-enabled digital devices has gained attention in recent years. Preliminary studies have demonstrated promising results, suggesting a potential decrease in microbial adhesion and growth on hydrophobic surfaces compared to conventional glass surfaces.[4,5] However, the hydrophobic property was not tested on mobile touch surfaces in reducing the microbial populations and their long-term effectiveness of such coatings in real-world scenarios. Hence, this study is aimed to evaluate the potential of hydrophobic surface on mobile phones in reducing the microbial build-up.

MATERIALS AND METHODS

Setting

This study was performed among healthcare workers in Saveetha Medical College and Hospital, Saveetha University, Chennai, a tertiary-care center with a capacity of 250 plus beds comprising 20 plus clinical departments and centers. Participants were included from undergraduate medical students willing to participate in this randomized study.

Selection and sampling

A total of 20 mobile phones were identified from undergraduate medical students willing to participate. The surface of the mobile phone (touch screen) was rubbed over using a sterile cotton swab from top to bottom and in diagonal. Contact with the sides of the mobile was ignored to avoid surface contact microbes. This swab was marked separately. Then, the mobile tough surface was disinfected using an alcohol swab; let it air dry. Further one half of the screen was covered using sterile gauze, and on the exposed half, commercially available liquid hydrophobic coating was sprayed over as per the manufacturer’s instructions. The mobile was handed over to user, and after 3 and 6 h, the same mobile was collected, and the surface was swabbed with a cotton swab for microbial load estimation. The samples were transported for bacterial culture and enumeration.

Questionnaire survey

The consenting participants were provided with a questionnaire which includes details of mobile phone usage at the hospital, duration of usage, use of personal phone at work, screen protector availability on device, type of screen protector, disinfection practices, hydrophobic surface of mobile surface, frequency of cleaning, type of cleaning agent, time interval between cleaning, hand wash frequency, and their awareness of microbial load on mobile surfaces. The responses were kept anonymous to keep participant’s privacy.

Microbial growth

The swab was dipped in sterile tryptone broth and spread on a nutrient agar plate. The inoculums were prepared at 10⁻³ dilution and plated on a Muller Hinton agar plate and further incubated for 24 h at 37°C. The microbial colonies were enumerated as cfu/ml.

Data analysis

The cfu/ml were enumerated and entered onto Microsoft Excel sheet. The mean and standard deviations were derived. The questionnaires’ data were analyzed using the Statistical Package for Social Sciences v. 14.0 software package and comparative analysis was performed using the Student t-test and the Chi-square test; P ≤ 0.05 was considered statistically significant.

RESULTS

A total of 20 samples were collected from hydrophobic and nonhydrophobic surfaces of mobile phones. All the study population were first-year undergraduate medical students with a mean age of 19.3 ± 0.8 years. A majority of 10 (50%) students were using Apple iPhone, followed by Samsung (n = 4, 20%), Oppo (n = 3, 15%), Vivo (n = 2, 10%), and Mi (n = 1, 5%) brands.

The microbial load was compared between nonhydrophobic and hydrophobic surfaces at different time intervals [Figure 1]. As it illustrates, the nonhydrophobic surface harbors gradual microbial build-up upon time, such as threefold increase from 2 to 4 h and fivefold increase to 6 h postinitial sampling with 143.6 ± 33.89 cfu/ml increase up to 264.7 ± 28.53 cfu/ml, whereas the hydrophobic surface had an overall build-up from 16.6 ± 1.2 to 50.45 ± 11.12 cfu/ml with P < 0.0001 significance.

Figure 1.

Microbial load on mobile touch surfaces with hydrophobic and nonhydrophobic surface. CFU = Colony forming unit, NH = nonhydrophobic surface, Hy = hydrophobic surface

DISCUSSION

Hydrophobic glasses offer a distinct advantage over conventional glass surfaces in terms of reducing microbial populations on touch-enabled digital devices. The hydrophobic coating applied to the glass surface creates a repellent barrier that prevents the adhesion of microorganisms and minimizes their growth and survival. This property is particularly beneficial for mitigating microbial contamination on devices that are frequently touched and handled by multiple individuals.[6,7]

The major advantage of hydrophobic glasses is their ability to repel water and other liquids. By repelling water, hydrophobic glasses significantly reduce the chances of microbial adhesion and the subsequent formation of biofilms.[8]

Upon hydrophobic coating, we detected a decreased microbial build-up as compared to the nonhydrophobic surfaces. This may be due to the fact that hydrophobic nature of these glasses limits the availability of nutrients for microorganisms. Many microorganisms rely on organic matter and moisture as sources of nutrition. By repelling water and reducing the accumulation of organic debris, hydrophobic glasses create an inhospitable environment for microbial growth. This deprives microorganisms of the necessary resources to thrive and multiply, further contributing to a decrease in microbial populations on device surfaces.

This study contributes to the new knowledge by exploring the effectiveness of hydrophobic surfaces in reducing the microbial population on touch-enabled digital devices. We found the impact of hydrophobic spray significantly reducing the microbial build-up. The research will involve controlled experiments using various microorganisms commonly encountered in everyday environments. Further, by evaluating the adherence and survival rates of these microorganisms on hydrophobic glass surfaces, valuable insights can be gained regarding the potential benefits of such coatings in enhancing the hygienic properties of touch-enabled digital devices. Overall, this research has significant implications for public health and hygiene.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.