Critical Issues in Sensor Science To Aid Food and Water Safety

Abstract

The stability of food and water supplies is widely recognized as a global issue of fundamental importance. Sensor development for food and water safety by nonconventional assays continues to overcome technological challenges. The delicate balance between attaining adequate limits of detection, chemical fingerprinting of the target species, dealing with the complex food matrix, and operating in difficult environments are still the focus of current efforts. While the traditional pursuit of robust recognition methods remains important, emerging engineered nanomaterials and nanotechnology promise better sensor performance but also bring about new challenges. Both advanced receptor-based sensors and emerging non-receptor-based physical sensors are evaluated for their critical challenges toward out-of-laboratory applications.

Dissipation enhanced vibrational sensing in an olfactory molecular switch

“…[31][32][33][34][35] The prevailing theory, known as the lock-and-key model, explains how the odorant size and shape can provide discrimination in the receptor. 36 However, this theory does not give a straightforward explanation of why it a) These authors contributed equally to the work.…”

Image Processing and Cell Phone Microscopy to Analyze the Immunomagnetic Beads on Micro-Contact Printed Gratings

“…There are also other powerful denoising algorithms such as the Karhunen-Loeve treatment (KLT) [26] and in order to improve the performance of the cell phone microscope, one of our future goals is to test KLT on the images. A critical issue of the emerging sensors is testing the sensor's performance in the field [27]. After improving the image processing algorithms, field tests of cell phone microscope-based sensing will be performed to compare the system's performance with the commercial systems in terms of the specificity and selectivity.…”

Detecting the stiffness and mass of biochemical adsorbates by a resonator sensor

“…Surface stress is the sensing mechanism for many receptor-based sensors [21,22]. However, the receptor-ligand binding is highly selective for identifying an adsorbate/ligand; the challenges for developing robust and stable recognition methods through functionalized coatings (i.e., the receptor materials) and even interpreting the responses of receptor-based sensor still remain [30]. The development for the receptor-less or receptor-free sensors, which bypass the chemistry of receptor-ligand binding and capitalize on the intrinsic material properties of adsorbate, has been called for [30].…”

“…However, the receptor-ligand binding is highly selective for identifying an adsorbate/ligand; the challenges for developing robust and stable recognition methods through functionalized coatings (i.e., the receptor materials) and even interpreting the responses of receptor-based sensor still remain [30]. The development for the receptor-less or receptor-free sensors, which bypass the chemistry of receptor-ligand binding and capitalize on the intrinsic material properties of adsorbate, has been called for [30]. Here the mass density (related with mass) and Young's modulus (related with stiffness) are the intrinsic material properties, which can be used to identify the material of an adsorbate.…”