Ft ir 8400 infrared spectrometer

Infrared spectra covering the spectral range 400–4000 cm⁻¹ were measured with a FT-IR 8400 infrared spectrometer (Shimadzu, Tokyo, Japan) equipped with a deuterated triglycine sulphate (DTGS) detector. Each spectrum was the average of 128 scans collected at 2 cm⁻¹ resolution. Samples were in the form of KBr pellets containing ca. 2 wt% of the material.

An FTIR-8400 infrared spectrometer (Shimadzu, Tokyo, Japan) equipped with a deuterated triglycine sulfate (DTGS) detector was used for the Fourier-transform infrared spectroscopy (FTIR) analysis. All spectra were recorded in the range of 400 to 4000 cm⁻¹ and were an average of 32 scans. All samples were in the form of KBr pellets containing ca. 2 wt% of the enzyme, the nanomaterials (PCC and PCCox), or the nano-biocatalysts. Equation (1) was used to calculate the correlation coefficient r in order to determine the similarity between two FTIR spectra [36 (link),37 (link),38 (link),39 (link)].
$r=\sum x_i{y}_i/\sqrt{\sum x_i^2\sum y_i^2},$
where x and y are the spectral absorbance values of free and immobilized enzyme, respectively, at the ith frequency position. For the calculation, the absorbance values of the spectra after smoothing in the region of 1600 to 1700 cm⁻¹ (amide region I) were used. The correlation coefficient r value will be equal to one (r = 1) for identical spectra.