A disposable ultrasensitive surface enhanced Raman spectroscopy biosensor platform fabricated from biodegradable zein nanofibers

Abstract

In this paper, a natural polymer, zein, is converted into a disposable and environmentally friendly surface enhanced Raman spectroscopy (SERS) biosensor platform to detect toxins. First, protein nanofiber mats were fabricated using electrospinning. Next, the surface of the fibers was decorated with metallic nanoparticles to create hotspots for the detection of the target molecule. Four types of metallic nanoparticles were tested for sensitivity optimization: gold, silver, silver‐shelled‐gold, and a mixture of gold and silver nanoparticles. Silver‐shelled‐gold nanoparticles gave the highest SERS intensity, and at the concentration of 1012 particles/ml, the highest enhancement factor (EF) of 2.49 × 106 was reached, which is the highest EF ever reported for a zein‐based biodegradable platform. Acrylamide was used as the model food carcinogenic toxin and its detection with this nanofiber‐based platform gave a limit of detection of 2.06 ng/ml. This LOD is 104 times lower than the limit of detection that was achieved previously with a zein‐based SERS platform. Other sensitive analytical methods (GC–MS and LC–MS/MS) gave LODs of 5–10 and 20–50 ng/ml for acrylamide, much higher than the method used in this study. This sensitivity is much lower than any other previous attempts to detect acrylamide with biodegradable sensors.

Incorporation of thermally induced shaped and phases of manganese oxide nanoparticles into zein/PVA fiber blends

“…Some acrylamide peaks are overlapping with some of the zein peaks. The peaks obtained for zein nanofibers for this study were in accordance with other reported studies [ [18] , [22] , [23] ].

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“…4 (c)) resulting from improved dispersion, increased surface area, conductivity, and stronger interaction between the nanoparticles and the composite fiber blends although the exact mechanism of growth and corresponding kinetics of the formation of such structures is not clear [ [15] , [20] , [21] ]. Article [ 22 ] studied four types of metallic nanoparticles (gold, silver, silver-shelled-gold, and a mixture of gold and silver nanoparticles) embedded into zein/acrylamide nanofibers. An increase in concentration of the nanoparticles was observed to have sufficient influence in the distribution uniformity of the nanofibers therefore this observation correlated to the morphological observations of the current study.…”

“…Therefore, manganese oxide was not observed around the fingerprint region. Article [ 22 ]. reported on the functional group peaks obtained from Raman spectroscopy.…”

Agro-Industrial Plant Proteins in Electrospun Materials for Biomedical Application

“…Based on the characteristics of electrospun matrix embedded components, biosensors with distinct functions are achievable. Highly enhanced sensitivity for the presence of carcinogenic acrylamide was obtained by fabricating zein mats decorated with the precise arrangement of gold and silver nanoparticles [ 39 ]. More recently, a biosensor based on electrodes coated with curcumin carbon dots and zein electrospun nanofibers, detected S. aureus in milk using electrical impedance spectroscopy [ 40 ].…”

Recent Development of Polymer Nanofibers in the Field of Optical Sensing

“…Figure 11 shows different types of polymer nanofiber Raman sensors for the detection of pH, the mixture of Sudan I, CV and MG molecules, and H 2 O 2, OCHO. (1) For biological applications, Zhao et al [15], Zhu et al [100], Turasa et al [101], and Wang et al [102] used nanofibers to detect various biological molecules, such as neurotransmitters, metabolites, toxins, and bacteria. They exploited the high surface area and biocompatibility of nanofibers to enhance the sensitivity and selectivity of their sensors.…”