In this study, the performance of basic and signal-enhanced Si IREs has been compared for measurements in a spectroscopy setup with a fibre-coupled tuneable QCL source. These IREs had V-shaped microgrooves etched on the underside for more efficient in-coupling of light, while the signal enhanced IREs also had micropillars on the top surface. The results are also contrasted with measurements done in a standard ATR-FTIR spectrometer, using an Alpha II spectrometer with a single-reflection diamond ATR crystal. Various concentrations of glucose (0-5000 mg/dl) in aqueous solutions were used to characterise the system performance.