(229c) Characterization of TiO2 Nanotubular Sensor for Detecting Tuberculosis Volatile Organic Compounds

One of the deadliest disease in the world is Mycobacterium tuberculosis (MTB)¹. In 2015 there were 10.4 million incident TB cases worldwide¹. Lack of low cost point-of-care methods for screening/diagnosis of the disease is one of the major issues contributing to this world wide spread disease. MTB microorganism releases two unique volatile organic compounds (VOC) as byproducts which are methyl nicotinate and p-anisate. Having a low cost device that can detect the presence of these two unique VOCs rapidly and accurately can help minimize the number of patients affected.

To take advantage of the presence of these unique VOCs, a hierarchical cobalt functionalized Titanium oxide nanotubular substrate has been made. In our previous work, we showed that at certain biased voltages methyl nicotinate and p-anisate will bind with functionalized TiO2 nanotubes². The sensor response is measured between the baseline current and the final current. Several variables affect the sensor response to VOCs, such as nanotubular morphology, the percentage of cobalt in the TiO2 nanotubes, the gas flow rate and both the concentration and volume of the VOC provided to the sensor.

In this work, we will present results of testing sensors with various morphologies at different volumes, flow rates and concentrations of the two biomarkers mentioned in order to characterize trends in sensor response. This will help us optimize our results from the field and measure the patient’s stage of disease. Sensor morphology and the amount of cobalt on TiO2 nanotubes will also affect the baseline current of the sensor. In order to improve the sensor’s performance, we will examine a range of baseline currents and its influence on reliability of the response and current signal to noise ratio. Detailed analysis of the sensor performance to different variable ranges will be presented.

1. Tuberculosis (TB) Data and Statistics. https://www.cdc.gov/tb/statistics/ Accessed 12/16/2016, 2016.
2. Bhattacharyya D, Smith YR, Misra M, Mohanty SK. Electrochemical detection of methyl nicotinate biomarker using functionalized anodized titania nanotube arrays. Materials Research Express 2015;2(2):025002.