Label-free novel platform for electrochemical detection of E. coli in tap water

Abstract

Waterborne infections such as hepatitis, diarrhea, encephalitis etc., are caused by viruses and remain the main cause of fatality worldwide. Diarrhea alone has led to 2.2 million deaths per year worldwide. These viruses are mostly transferred by fecal-oral passage, causing waterborne diseases. The World Health Organization (WHO) estimates that waterborne pathogens contribute to 4% of the diseases worldwide which highlights a critical need to search for efficient methods to detect these pathogens in a robust and rapid manner. Thus, by employing a sensitive platform that can improve the limit of detection (LOD) by manifolds, the aim is to detect the virus timely and thus reduce disease prevalence. Here Zeolite imidazolate framework (ZIF) a type of MOFs with bimetallic transition elements, has been used to improve electrocatalytic performance and ability to detect pathogens without the need of using labels such as enzymes, fluorescent tags etc. We report an ultrasensitive electrochemical sensor based on NiCoZIF/CNTs to detect low concentrations of E.Coli in tap water where the LOD is reported as 0.37 CFU/mL. The sensing platform has also been morphologically and electrochemically studied. This sensor has clear practical applications such as public health, water quality monitoring and food safety.