Quantum Dot-Enabled Biosensing of E. coli for Waterborne Pathogen Detection
By Holly
The proposed research aims to explore the development of a carbon quantum dot-based detection system for Escherichia coli (E. coli). It builds off the findings and methodology of a 2023 QLab project and aims to refine methods to improve sensitivity. Quantum dots are versatile nanomaterials with unique optoelectronic properties due to its broad absorption bands. The optical properties of these nanomaterials are size-tunable and can be adjusted in a specific range of the electromagnetic spectrum by changing size.
Intellectual Merit
The intellectual merit of this study lies in advancing ongoing efforts in nanomaterials for precise biodetection. Traditional culture-based and immunological assays are reliable, but slow means of identifying E. coli contamination. Molecular methods, such as polymerase-chain reaction (PCR), can accelerate detection, but require specialized equipment and extensive technical expertise. These methods are labor-intensive, time-consuming, and inadequate for point of care water screening. The development of quantum dots (QDs), nanoparticles with unique electronic structures that confer narrow, size-dependent emission spectra under excitation, present a new avenue of research. Previous demonstrations of nanoparticle-biomolecule conjugation suggest that these fluorophores could be adapted for biosensing applications, yet achieving organism-specific recognition, particularly to E. coli, remains a challenge. This project seeks to develop a novel method for specifically conjugating carbon QDs to E. coli and exploiting the fluorescence properties of QDs for rapid detection.
Broader Impact
The capacity to rapidly and affordably detect E. coli has far reaching implications for public health, environmental safety, and social equity. Globally, unsafe water, poor sanitation, and inadequate hygiene remain among the leading contributors to diarrheal disease and mortality, especially in low-income regions. According the the Centers for Disease Control and Prevention (CDC), waterborne pathogens are estimated to cause over 7 million illnesses, 118,000 hospitalizations, 6,630 deaths, and direct healthcare costs exceeding $3.3 billion annually in the United States alone. Approximately 1.6 million people die each year from waterborne diseases worldwide. By identifying a novel system of on-site, low-cost, and rapid detection of E. coli, the proposed QD biosensor system could transform water quality monitoring practices.