We report on the development of a highly sensitive and novel surface enhanced Raman scattering (SERS) substrate for the detection of analytes, such as rhodamine 6G (R6G), glyphosate, melamine and salicylic acid. The fabrication steps include (a) cleaning the surface of the Cu-grids on carbon support layer with an initial glow discharge treatment, (b) layering of carbon film with a thickness of 3nm, (c) application of 24μl volumes of silver colloid to form silver dendrites, and (d) a glow discharge treatment of silver dendrites to remove surface debris or particles. The substrate demonstrated excellent SERS measurement reproducibility, along with a significant SERS enhancement factor of 6.1×105 of Raman signals and highly informative chemical signature of R6G. The SERS substrate can be used as a quantitative tool. The protocols for fabrication of the substrate are inexpensive and it is more sensitive than conventional Raman technique and a commercial product. Highly sensitive detection limits for R6G (240ppb), glyphosate (845ppb), melamine (630ppb) and salicylic acid (600ppb) were achieved with this substrate. This study has shown that the Ag-Cu-grid substrate is well suited for routine environmental monitoring of chemical residues and the detection of plant metabolites. The stability of the nano-structured Ag-Cu-grid was demonstrated during a 4 week storage period.

Dried, milled perennial ryegrass samples were processed using chemical and physical treatments and the extracted cellulose products were analysed for yield, crystallinity by X-ray Diffraction (XRD) and for purity using Thermogravimetric Analysis (TGA), Pyrolysis-Gas Chromatography/Mass Spectrometry (Py-GC/MS) and Fourier Transform Infrared (FTIR) spectroscopy. Extraction protocols examined the use of chemical chelation, acid and alkaline hydrolysis, along with physical degradation methods. Highest product yields were obtained using single step chemical protocols followed by physical processing, however, these products had low crystallinity and higher amorphous fraction content. Multistep chemical processing to completely remove hemicellulose and lignin with an alkali refluxing step, delivered lower yielding cellulose products of greater crystallinity and purity. In combination, the four instrumental techniques highlighted removal of amorphous fractions, providing rapid, accurate compositional data on the extracted cellulose products.

The biorefining of grass offers an opportunity to integrate primary production agriculture with the extraction of fibre. The study was aimed at developing protocols for processing ryegrass to determine fibre content and to generate visible and near infrared reflectance (Vis–NIR) calibrations for estimating fibre fineness with the aid of a new reference airflow method. The method for determining fineness of processed fibres has been adapted from flax fibre protocols. A Vis–NIR calibration using partial least squares (PLS) regression method was employed to generate models with a calibration set consisting of 85 samples obtained from fresh and ensiled grasses. The PLS model was successfully validated with 21 independent samples with a prediction error of 1.26dtex. An optimised PLS model (r2=0.86) consisting of 106 samples has been developed. The quality assurance protocols could be used for assessing fibre content and quality of silage, hay and fresh grass.