Abstract
The creation of label-free biosensors capable of accurately detecting trace contaminants, particularly small organic molecules, is of significant interest for applications in environmental monitoring. This is achieved by pairing a high-sensitivity signal transducer with a biorecognition element that imparts selectivity towards the compound of interest. However, many environmental pollutants do not have corresponding biorecognition elements. Fortunately, biomimetic chemistries, such as molecular imprinting, allow for the design of artificial receptors with very high selectivity for the target. Here, we perform a proof-of-concept study to show how artificial receptors may be created from inorganic silanes using the molecular imprinting technique and paired with high-sensitivity transducers without loss of device performance. Silica microsphere Whispering Gallery Mode optical microresonators are coated with a silica thin film templated by a small fluorescent dye, fluorescein isothiocyanate, which serves as our model target. Oxygen plasma degradation and solvent extraction of the template are compared. Extracted optical devices are interacted with the template molecule to confirm successful sorption of the template. Surface characterization is accomplished via fluorescence and optical microscopy, ellipsometry, optical profilometry, and contact angle measurements. The quality factors of the devices are measured to evaluate the impact of the coating on device sensitivity. The resulting devices show uniform surface coating with no microstructural damage with Q factors above 106. This is the first report demonstrating the integration of these devices with molecular imprinting techniques, and could lead to new routes to biosensor creation for environmental monitoring.
Highlights
Environmental pollutants, and, in particular, emerging environmental pollutants, such as agricultural contaminants and veterinary pharmaceutical by-products, represent one of the largest and most challenging classes of pollutant chemicals that can have a significant, detrimental impact on human health and the environment
Study were initially designed to device target plasma, which is typically used for devices cleaningfabricated residue from is simple, minimizes the order to create artificial receptors for this fluorescent dye,the a molecular imprinting handling, and doesInnot require post-treatment to remove excess water from surface
Integration of the artificial receptors with resonators was the hand, O2 plasma treatment might not yield as high of a surface hydroxyl density as piranhaprimary etching, challenge; the primary goal of this study was to demonstrate the creation of a thin, uniform causing a lower adhesion of the coating to the surface
Summary
Environmental pollutants, and, in particular, emerging environmental pollutants, such as agricultural contaminants (pesticides, herbicides, etc.) and veterinary pharmaceutical by-products, represent one of the largest and most challenging classes of pollutant chemicals that can have a significant, detrimental impact on human health and the environment. Pesticides and herbicides are classified by Environmental Protection Agency as two of the most toxic classes of environmental pollutants [1,2,3]. It is essential to have an accurate method that is capable of trace detection of these pollutants in food and water systems. Biosensors 2016, 6, 26 pollutants is chromatography, including GC-MS and HPLC, which can accurately detect and identify these compounds from water samples extracted from the environment [6]. Significant improvement is needed to address the ever-increasing complexity and pervasiveness of environmental pollutants in food and water systems
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
