Monitoring growth and antibiotic susceptibility of Escherichia coli with photoluminescence of GaAs/AlGaAs quantum well microstructures

• Published in: Biosensors & bioelectronics 2017-07, Vol.93, p.234-240
• Main Authors: Nazemi, Elnaz, Hassen, Walid M., Frost, Eric H., Dubowski, Jan J.
• Format: Article
• Language: English
• Subjects: Anti-Bacterial Agents - chemistry; Anti-Bacterial Agents - pharmacology; Antibiotic susceptibility; Arsenicals - chemistry; Bacteria; Biosensing Techniques; Drug Resistance, Bacterial - drug effects; Engineering Sciences; Escherichia coli; Escherichia coli - drug effects; Escherichia coli - isolation & purification; Gallium - chemistry; Humans; Luminescence; Microbial Sensitivity Tests; Photocorrosion; Photoluminescence; Quantum Dots - chemistry; Quantum semiconductors
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2016.08.112

Development of quick and reliable methods to investigate antibiotic susceptibility of bacteria is vital to prevent inappropriate and untargeted use of antibiotics and control the antibiotic resistance crisis. The authors have developed an innovative, low-cost and rapid approach to evaluate antibiotic susceptibility of bacteria by employing photoluminescence (PL) emission of photocorroding GaAs/AlGaAs quantum well (QW) biochips. The biochips were functionalized with self-assembled monolayers of biotinylated polyethylene glycol thiols, neutravidin and biotinylated antibodies to immobilize bacteria. The illumination of a QW biochip with the above bandgap radiation leads to formation of surface oxides and dissolution of a limited thickness GaAs cap material (≤10nm) that results in the appearance of a characteristic maximum in the PL plot collected over time. The position of the PL maximum depends on the photocorrosion rate which, in turn, depends on the electric charge immobilized on the surface of the GaAs/AlGaAs biochips. Bacteria captured on the surface of biochips retard the PL maximum, while growth of these bacteria further delays the PL maximum. For the bacteria affected by antibiotics a faster occurring PL maximum, compared with growing bacteria, is observed. By exposing bacteria to nutrient broth and penicillin or ciprofloxacin, the authors were able to distinguish in situ antibiotic-sensitive and resistant Escherichia coli bacteria within less than 3h, considerable more rapid than with culture-based methods. The PL emission of the heterostructures was monitored with an inexpensive reader. This rapid determination of bacterial sensitivity to different antibiotics could have clinical and research applications. [Display omitted] •Innovative monitoring of bacterial growth on biofunctionalized semiconductor chips.•Evaluation of antibiotic susceptibility of E. coli and eventually other bacteria.•Time-to-results less than 3 h.•Potential for application to clinical diagnostic laboratories.•Potential for rapid identification of effective antibiotics.