A spectrophotometer is an analytical instrument used to measure the intensity of light at different wavelengths. It is widely used in various fields such as chemistry, biochemistry, physics, and molecular biology to quantify the concentration of analytes in a sample by measuring the absorbance or transmittance of light. According to the wavelength range, spectrophotometers can be divided into UV spectrophotometers (200-400nm), visible spectrophotometers (400-700nm), and near-infrared spectrophotometers (700-1100nm).