(733f) Detection of a Peanut Allergen, Ara h1, on a Novel, Biodegradable Biosensor Platform Using Surface Enhanced Raman Spectroscopy

Food allergy is one of the major health issues related to food as the consequences can be lethal for susceptible populations. Peanuts (Arachis hypogea) are one of the leading agents of food allergy. Among the eight (Ara h1 to h8) identified peanut allergen proteins, Ara h1 has been found to affect up to 100% of the allergic patients [1]. Since allergens should always be monitored for cross-contamination, development of rapid, on-site diagnostic tools is very beneficial for the food industry [2]. Due to their high speed, ease of use and high degree of automation, biosensors present an alternative solution to the allergen detection problem. For this reason, a nano-biosensor that utilizes Surface Enhanced Raman Spectroscopy (SERS) was investigated to detect and identify Ara h1 allergen protein. SERS makes use of noble metals, mostly gold and silver, with a rough feature to create intensified Raman signals, which gives molecular level information of analytes. Roughness is generally created by either nanoparticles or regular nano-patterns. Here we utilize this highly specific technique to detect Ara h1. The novelty of the biosensor comes from the unique biomaterial that it is made of, zein. Zein is a corn prolamin, which has shown to form free-standing films and capable of replicationg micro and nano-scale features [3,4]. In this research, biosensors were obtained by direct transfer of 3D structures (pyramids) with a gold coating onto zein films [5]. By using Raman spectroscopy, the signature of Ara h1 protein was identified and a calibration curve was obtained for different concentrations. We propose that in the future SERS technique could be used to identify and monitor allergen proteins with the help of an environmentally friendly platform of zein.

References

[1]. Burks, A.; Williams, L. W.; Connaughton, C.; Cockrell, G.; O'Brien, T. J.; Helm, R. M. Identification and characterization of a second major peanut allergen, Ara h II, with use of the sera of patients with atopic dermatitis and positive peanut challenge. J. Allergy Clin. Immunol., 1992, 90, 962-969.

[2]. McGrath, T.; Elliott, C.; Fodey, T. Biosensors for the analysis of microbiological and chemical contaminants in food. Analytical and bioanalytical chemistry, 2012, 403, 75-92.

[3] Luecha, J.; Hsiao, A.; Brodsky, S.; Liu, G. L.; Kokini, J. L. Green microfluidic devices made of corn proteins. Lab on a Chip, 2011, 11, 3419-3425.

[4] Altunakar, B.; Luecha, J.; Kokini, J. In In Fabrication of biodegradable zein films by using soft lithography; Proceeding Nanotechnology Conference, Anaheim, 2010, 2, 253-256.

[5] Hsiao, A.; Gezer P.G.; Kokini, J.L.; Liu G.L. Green Nanophotonic Sensor Made by Direct Transfer of Three-Dimensional Metallic Nanostructures onto Corn Protein Film, J. Nanotechnology 2014, submitted