Research Projects

Sepsis is a medical emergency that occurs due to infection caused by severe bacterial and fungal infections resulting in organ failure that leads in to 20% of mortality globally. The sepsis causing bacterial pathogens are Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, Pseudomonas aeruginosa, and Streptococcus pyogenes, and fungal pathogens i.e. Candida species. Existing gold standard in diagnostic of sepsis rely on blood culture based, are time-consuming from 24 - 48 hours or more depending of pathogen’s type and concentration requiring 20-40ml of blood. Moreover, the overprescription of antibiotics has significantly increased the development of antimicrobial resistance in most pathogens making it difficult to treat on timely manner. There is an unmet need to develop rapid and accurate diagnostic device that is capable to detect sepsis causative pathogens in minimal (0.5-1ml) amount of blood at onset of symptoms and determine their antibiotic susceptibility. Therefore, the objective of this work is to develop a rapid chip based diagnostic device using graphene transistors for multiplexed detection of sepsis causative pathogens and their antimicrobial resistance. This will involve the design and fabrication of a GFET chip consisting of 6 sets of sensors each having 3 sensing elements to simultaneously detect 5 different pathogens and a control. The five sets of sensors will be functionalized with 5 different pathogen specific probes (aptamers, peptides, nanobodies). The binding of bacteria to the surface of graphene will modulate channel conductance and its quantum capacitance that will be measured using impedance analyzer. Moreover, the capacitance measurement is helpful in determine the resistance vs susceptible bacteria because of significant difference in thier dielectric properties caused by gene mutation and cell wall modification. The capacitance vs voltage/frequency plots will be recorded to obtain the best optimum characteristics to detect all the five bacterial pathogens individually and their sensitivity and specificity will be determined. Finally, the multiplexed detection of all the bacteria will be performed from mixture made with varying concentrations of all the pathogens. Then, the clinical feasibility will be tested by spiking these bacteria in serum samples.The significance of the this research upon successful demonstration will solve a major challenge of rapid diagnosis of Sepsis and the developed antimicrobial resistance that will result in reduced mortality.