▎ 摘　　要

NOVELTY - The chip has a glass substrate, a silver layer, an indium tin oxide layer and a gold layer that are formed with each other, where the glass substrate is made of a BK7 material with a high refractive index, thickness is about 1 mm, thickness of a silver layer is between 10 nm-30 nm, a thickness of an indium tin oxide layer is 20 nm-50 nm, and thickness of the gold layer is 5 nm-20 nm. The silver layer realizes main resonance action. The gold layer realizes secondary resonance and protects the indium tin oxide layer. The silver layer and the gold layer generate double resonance phenomenon to form a laminated structure. USE - Laminated SPR biological sensing chip for detecting refractive index change of substance by using photoelectric effect. Uses include but are not limited to food, medicine, biological medicine and gas detection field. ADVANTAGE - The chip avoids graphene as sensitization material and difficult to control the preparation and coating, so as to steer the mature semiconductor material of indium tin oxide, thus reducing the preparation cost of the high-sensitivity chip. The chip has higher sensitivity by conductivity and semiconductor performance of the indium tin oxide. The outermost layer of gold layer protects indium tin oxide without mildew.