Peptide conjugated cellulose nanocrystals with sensitive human neutrophil elastase sensor activity

Nanocellulose-Based Biosensors: Design, Preparation, and Activity of Peptide-Linked Cotton Cellulose Nanocrystals Having Fluorimetric and Colorimetric Elastase Detection Sensitivity

“…Figure 6 portrays the color change of the nanocrystals upon amplification of the colorimetric response when para-nitroaniline is released from the peptide and reacts with a color amplifying reagent. As shown recently for the reaction of elastase with the peptide-nanocellulose conjugates there is a strong color response associated with the amplification reaction of para-nitroaniline with amplifying reagents [31]. The images of the nanocrystalline sensor following incubation with elastase demonstrate the visual color response positive for the presence of elastase activity.…”

“…Thus, the in situ detection of HNE and other proteases through dressing design motif is of potential diagnostic value in providing improved healing resolution in chronic wounds. Figure 4 shows a model of a peptide-conjugated nanocrystal constructed from a "minimal size" cellulose nanocrystal containing 180 anhydroglucose units, and constructed to reflect the proximal DS level on the nanocrystalline surface observed (0.06) as recently reported [31]. The molecular model portrays the putative accessibility of the peptide substrate on the surface of the nanocrystal by serine protease elastase.…”

“…Figure 3 shows the synthesis of the peptide-cellulose conjugate. Peptide incorporation on cotton cellulose nanocrystals was characterized with DS levels ranging from 0.02 -0.06 using the approach described for colorimetric elastase sensors [31]. The relationship of the specific surface area to the DS levels for these types of conjugates has been characterized in terms of derivatization of available hyroxymethyls on the surface of the nanocrystal.…”

“…Although the pNA substrate is highly specific for elastase the AMC substrate is much more sensitive. Fluorescent elastase substrates attached to cotton cellulose nanocrystals have recently been prepared similar to a colorimetric HNE sensor reported [31] and shown to be sensitive to low levels of elastase concentrations. Figure 5 shows the fluorescent response of 2 milligrams of a tetrapeptidenanocellulose analog prepared from cotton cellulose nanocrystals upon incubation with human neutrophil elastase.…”

“…These types of adducts may have potential as point of care diagnostics where incubation times are minimized [3]. This type of sensor approach has also been aligned with dialysis cellulose membranes to demonstrate the potential for in situ wound dressing use [31].…”