(337c) Point-of-Care Fungal Pathogen Identification Using Surface Acoustic Waves Coupled with Metal-Enhanced Fluorescence | AIChE

(337c) Point-of-Care Fungal Pathogen Identification Using Surface Acoustic Waves Coupled with Metal-Enhanced Fluorescence


Samuelson, J. - Presenter, University of South Florida
Bhethanabotla, V., University of South Florida
Donovan, C., Morsani College of Medicine, University of South Florida Eye Institute
Ayyala, R. S., University of South Florida
Corneal ulcers, typically caused by infection, are among the leading causes of vision loss and require prompt intervention. Without effective treatment, permanent vision impairment[i] and more serious infections[ii] can result. Rather than spending days culturing the pathogen to determine whether the infection is bacterial or fungal, antibiotics are typically applied as an empiric treatment[iii]; as the incidence of fungal infections increases, however, complications are becoming more prevalent[iv]. The two types of infection may instead be rapidly distinguished at point-of-care by means of a self-contained acoustic isolation and detection system, allowing doctors to immediately prescribe the appropriate remedy. The core of this system is a piezoelectric chip made from a material such as quartz or LiNbO3 whose surface is functionalized with a chitin-binding lectin having a strong affinity for the cell walls of fungal pathogens. By electrically exciting this chip, Rayleigh waves lyse pathogen cells, mix the sample, and remove nonspecifically-bound materials[v], purifying chitin and isolating it on the chip’s surface. The isolated analyte is then detected using a chitin-sensitive fluorescent probe. The detection limit may be further improved by means of metal-enhanced fluorescence using a thin layer of silver nanostructures formed by rapid thermal annealing that couple with the probe signal[vi]. This technique has proven effective with other analytes at concentrations on the order of picograms per milliliter[vii].

[i] McClintic, S. M., et al. "Improvement in corneal scarring following bacterial keratitis." Eye 27.3 (2013): 443-446.

[ii] Scott, Ingrid U., et al. "Endophthalmitis associated with microbial keratitis." Ophthalmology 103.11 (1996): 1864-1870.

[iii] Collier, Sarah A., et al. "Estimated burden of keratitis—United States, 2010." MMWR. Morbidity and mortality weekly report 63.45 (2014): 1027.

[iv] Tuberville, Audrey W., and Thomas O. Wood. "Corneal ulcers in corneal transplants." Current eye research 1.8 (1981): 479-485.

[v] Cular, Stefan, et al. "Removal of nonspecifically bound proteins on microarrays using surface acoustic waves." IEEE Sensors journal 8.3 (2008): 314-320.

[vi] Morrill, Samuel, Venkat Bhethanabotla, and Mandek Richardson. "Biomarker quantification at clinically relevant concentrations using metal enhanced fluorescence combined with surface acoustic waves." SENSORS, 2014 IEEE. IEEE, 2014.

[vii] Liu, Jun, Shuangming Li, and Venkat R. Bhethanabotla. "Integrating metal-enhanced fluorescence and surface acoustic waves for sensitive and rapid quantification of cancer biomarkers from real matrices." ACS sensors 3.1 (2018): 222-229.