Selectivity and reusability study of functionalized ALD TiO2 evanescent wave sensors

The monitoring of bacteria concentration in drain fluid is the most common way to estimate the success of a colon surgery. The lack of efficient method to follow the development of E. coli in drain fluid after surgery is often fatal to the patient. Together with the first clinical symptoms, bacteria are an early and reliable indicator of anastomotic leakage one to three days after surgery. The proposed device helps to significantly reduce the diagnostic time to a few minutes, while providing a low cost solution. It uses an ALD TiO₂ evanescent sensor properly functionalised. The selectivity of the sensor to Bacillus Subtillus is demonstrated and a minimum detection of 10³ CFU/ml is measured. The sensors can be properly cleaned and reused up to 10 times without major deterioration of their performance.