Title: Exploring biosensor applications with cotton cellulose nanocrystalline protein and peptide conjugates Authors
Submitted to: New Orleans Carbohydrate Symposium
Publication Type: Abstract Only
Publication Acceptance Date: November 2, 2012
Publication Date: N/A
Technical Abstract: Sensor I: Nano-crystalline preparations were produced through acid hydrolysis and mechanical breakage of the cotton fibers from a scoured and bleached cotton fabric and a scoured and bleached, mercerized fabric, which was shown to produce cellulose I (NCI) and cellulose II (NCII) crystals respectively. Scanning electron microscopic images of the enzyme conjugates of NCII also revealed uniformly smaller particles than the NCI counterparts. The covalent incorporation of lysozyme conjugated to the NCI and NCII preparations was up to 10 fold greater than lysozyme covalently conjugated to whole cotton fabric with extraordinary high activity (1500 U/ mg cotton). Sensor II: A Human Neutrophil Elastase (HNE) tripeptide substrate, n-Succinyl-Alanine-Alanine-Valine-para-nitroanilide (Suc-Ala-Ala-Val-pNA), was covalently attached to glycine esterified NCI and compared with a similar tetrapeptide analog for colorimetric HNE sensor activity. Visible HNE activity was significantly higher on NCI tripeptide conjugates when compared with similar analogs synthesized on paper. Upon enzymatic release of para-nitroaniline (pNA) from the Glycine-CCN conjugate of succinyl-Ala-Ala-Val-pNA, amplification of the colorimetric response from pNA with reactive dyes enhanced visible absorption of the chromogen. The HNE sensor and the chromogen amplifying dyes were interfaced with 50 and 10 kD dialysis cellulose membranes (DCM) to model filtration of HNE and chromogen (pNA) from a model wound dressing surface before and after sensor reactivity. The detection sensitivity to HNE activity was assessed with the NCI-tripeptide conjugate interfaced at the DCM surface distal and proximal to a dressing surface. The HNE sensor interfaced proximal to the dressing surface was most efficient with 10kD membrane filtration of pNA and subsequent reaction with amplifying dyes. When interfaced with the 10kD cellulose membrane, elastase sensor activity remained sensitive to 0.05 U/mL HNE. The performance and design issues of each biosensor/NCI approach are discussed.