Novel spider web trap approach based on chitosan/cellulose nanocrystals/glycerol membrane for the detection of Escherichia coli O157:H7 on food surfaces

Fabrication of Janus-type nanocomposites from cellulose nanocrystals for self-healing hydrogels' flexible sensors

Janus bio-nanomaterials have great application potential in functional solid surfactants, probes and flexible sensors. In this manuscript, the sustainable Janus cellulose nanocrystals-type (CNCs-type) nanomaterials were prepared by Pickering emulsion template method. The asymmetric functionalism of Janus nanorods was realized by asymmetrically grafting polypyrrole (PPy) and polydopamine (PDA) onto different sides of CNCs (Janus CNCs-PPy /PDA (JCNs)). JCNs was successfully applied to self-healing nanocomposite hydrogels and further applied to the development of flexible sensors. The self-healing efficiency of nanocomposite hydrogels was 87.2%, and the stress and strain reached 3.50 MPa and 453.45%, respectively. It is worth noting that flexible sensors have been widely used in the field of wearable electronic sensing for real-time monitoring of human movement due to their high sensitivity (gauge factor (GF) = 9.9) and fast response time (260 ms).

Performance of chitosan polymer as platform during sensors fabrication and sensing applications

Chitosan is an important polymer produced from deacetylation of several sea and insects crusts. Due to its environmental fate and biological biocompatibility, it can be used in several biological and environmental applications. Sensing of biological compounds in human bodies and also in serum, blood, and different body fluids has found an important application instead of direct determination of the body fluids using complicated tools. Sensing process of biological compounds during bio-analysis of the biological systems, especially human fluids lack of several parameters including: high sensitivity, repeatability, speed of analysis and biocompatibility of the used analytical methods, especially in-vivo analysis. That was due to the time between sample handling and sample determination can change various components and concentrations of the bio-compounds. The need for in-situ analysis was directed the researchers for biosensors to overcome the upgrading problems of bio-analysis. Biosensors were the future of this issue. Chitosan can reserve as great platform for fabrication of different sensors to determine the elements, compounds and body bioactive compounds. The presence of different terminal amino and hydroxyl groups within chitosan framework facilitates the immobilization of different biomarkers to be used as sensing elements for the determined compounds. The use of chitosan as sensors platform was enhanced by using chitosan in its nanoforms.

Recent advances in cellulose-based membranes for their sensing applications

ABSTRACT

In recent years, sensing applications have played a very important role in various fields. As a novel natural material, cellulose-based membranes with many merits can be served as all kinds of sensors. This review summarizes the recent progress of cellulose membranes as sensors, mainly focusing on their preparation processes and sensing properties. In addition, the opportunities and challenges of cellulose membrane-based sensors are also prospected. This review provides some references for the design of cellulose membrane materials for sensing applications in the future.