Dr. Suryani Dyah Astuti, M.Si together with Surya, one of her students, demonstrate E-nose at the Biophysics Laboratory, FST UNAIR, Campus C. (Photo: Asthesia Dhea)
UNAIR NEWS – From time to time, the way to detect disease in teeth is only when it feels painful and in severe condition. It is the same for detecting food spoilage, which can only be seen and touched and sometimes it is still deceiving.
It inspired Dr. Suryani Dyah Astuti, M.Si., with Anak Agung Surya Pradhana team in collaboration with Dr. Kuwat Triyana from Gadjah Mada University to develop Electronic Nose (E-Nose). A device for early detection of dental and oral diseases as well as food quality.
“E-Nose is currently developed at UGM by Dr. Kuwat. He is working with the National Police Headquarters to detect drugs, “said Suryani.
With Suryani, Kuwat shared about the potential of E-Nose for early detection of disease as UNAIR is a university that excels in health science. Further discussion done with the dentist, Prof. Dr. Ernie Maduratna Setiawatie, drg. M.Kes. Sp. Perio (K) from Faculty of Dental Medicine (FKG) UNAIR even motivated her to deepen and implement the use of the gas array sensor.
Prof. Ernie, a lecturer and dentist at FKG UNAIR, said that so far most patients come to the doctor when their teeth are painful. Thus, early detection is necessary so that it can be anticipated.
Suryani explained that E- Nose is a device that mimics the workings of human nasal olfactory. Technically, the device uses a gas sensor responding to certain scents.
The response of the signals produced by E-Nose to a particular aroma will be analyzed using pattern recognition software, so that it can be analyzed and identified. Compared to other analytical techniques, such as gas chromatography, an electronic nose system can be built and can provide sensitive and selective analysis in real time.
Two stages of research
E – Nose research for early detection of dental disease consists of two stages, in vitro (laboratory scale) and clinical stage. In vitro stage aimed at E – Nose learning on aroma of bacteria causing dental disease. This stage has been carried out by alumni of S2 Biomedical Engineering Yanuar Mukhammad and Sirlus with the second supervisor Dr. Riries Rulaningtyas. Further research for E- Nose improvement done by Anak Agung Surya Pradhana, a student of Biomedical Engineering Master’s program UNAIR.
Surya explained, on the E – Nose there are six gas sensors working like a person’s nose receptors and memory. From the receptor, the data is sent to the database. That data is then used to train E – Nose with statistical algorithms decision tree. So that E-Nose is able to classify samples.
“In vitro research on a laboratory scale serves to collect gas data that will be used as a study of characteristics from various bacteria causing dental disease, such as S. mutant bacteria, Aa, P. Gingivalis, E. faecalis and other bacteria, “explained Surya.
“The algorithm used to train the E – Nose classifies certain bacteria based on the gas pattern produced. The results of pattern recognition training using the algorithm in vitro are used as references for e-nose clinical testing, “he added.
Surya added, the conducted in vitro tests showed good results. Various bacteria produce different odor concentrations depending on the number of days of storage. The study used sensors MQ2, MQ3, MQ7, MQ8, MQ 135, and MQ 136 which have different characteristics. For example, the MQ 135 sensor is specific for detecting ammonia.
“So there are specific sensors for carbon dioxide and some for ammonia. In dental bacteria generally the odor produced is a type of ammonia. The results of tests on biofilms of various dental bacteria showed different physical characteristics in various bacteria. Tests on chickens fed with E-coli showed significant differences compared to without E. coli,” he added.
How to use
Dyah said that the study used a special gas array sensor. For dental disease detection, it is recommended to use biofilm samples taken from the teeth / gums of the patient and grown on media. The method will produce data specific to certain bacterial characteristics.
Another method uses saliva samples. However, the use of saliva produces less specific data, because the odor produced does not only come from microbes that cause dental disease.
Besides for health, E- Nose has also been widely used for the detection of food quality, such as the quality of milk, meat, fish, chicken, and other food. The detection of chicken meat quality by Haidar Tamimi with the second supervisor Dr. Miratul Khasanah, M.Si. showed different patterns of gas detected by the sensor for their decreasing quality of meat based on the shelf life and activity of bacteria recognized by the E – Nose.
“By using this sensor, we can classify meat quality based on shelf life and the activity of types of bacteria that contaminate food ingredients. And it turns out, the longer the shelf life of chicken meat does not guarantee increased gas concentration, because at certain hours the protein contained in chicken meat has run out. So every hour there is a typical pattern of gas produced. E – Nose able to distinguish the quality of chicken meat, ” she said.
With this research, Dyah hoped to produce innovation-based works that can be utilized by the public at low prices. (*)