Model uv 2600

The pectate lyase activity was measured by incubating 100 μl of crude Protein with 900 μl of assay buffer containing pectin 1% at 50 °C for 10 min. The amount of galacturonic acid released under assay conditions was estimated following the Dinitrosalicylic acid (DNSA) method^{21 (link)}. The absorbance of the reaction was measured at 540 nm on a spectrophotometer (Model UV-2600; Shimadzu, Japan). The pectate lyase activity was determined by comparing the values with the standard graph prepared from the known concentration of galacturonic acid. The total protein was measured using the Lowry method^{22 (link)} by considering absorbance at 650 nm. The standard graph was prepared using bovine serum albumin as standard. One unit of pectate lyase activity was monitored by the amount of enzyme required to liberate 1 μmol of galacturonic acid per ml per minute under assay conditions (1U = 1 μmol/ml/min). Specific activity was defined by the enzyme unit per milligram (mg) of Protein.

H₃L was purchased from Jinan Henghua Technology Co., Ltd., Shan Dong, China. All other chemicals were purchased commercially and applied directly. Perkin-Elmer 240 element analyzer (PerkinElmer, Dublin, Ireland) is used for microanalysis of C, H and N elements. The ultraviolet-visible spectrophotometer (model UV-2600) manufactured by Shimadzu Company (Shimadzu, Kyoto, Japan), was used to measure the absorption spectra at room temperature, with the test wavelength ranging from 200–800 nm. Powder X-ray diffraction analysis was characterized by Rigaku D/Max-2500 (Rigaku, Tokyo, Japan) X-ray diffractometer equipped with Cu-Kα radiation at a wavelength of 0.154 nm. Photo-luminescence lifetimes and solid-state fluorescence spectra were measured by FS5 fluorescence spectrometer (Edinburgh Instruments, Edinburgh, UK). The RF-5301 fluorescence spectrophotometer (Shimadzu, Kyoto, Japan) was used to carry out the photo-luminescence sensing experiment, equipped with a plotter unit and 1 cm × 1 cm quartz battery in phosphorescent mode.