General objectives:
Design and fabrication of fiber-optic sensor devices with coating surface functionalization to improve the selectivity of the object to be measured (insecticides, herbicides, fungi, biological agents, etc.) can be used many times to control harvested products in high-tech agriculture.
Detail objectives:
Fabrication of fiber-optic sensors based on Bragg grating components in Etched Fiber Bragg grating - e-FBG with surface functionalization to improve the selectivity of objects to be measured for application control of harvested products in high-tech agriculture.

- Technological results: We successfully designed and fabricated an optical sensor probe based on Etched Fiber Bragg grating (e-FBG) by using two methods of chemical etching and mechanical abrasion. The proposal fiber ring laser using e-FBG, which operates like optical sensor, increases sensitivity of sensor. This optical sensor system is capable of determining different types of gasolines with different octane numbers and organic solvent concentration in gasoline blended specifically in the low concentration range of 0% - 14% by volume with mixture concentration accuracy of 0.2% and 0.15% for ethanol and methanol, respectively. To confirm the feasibility of the determination of nitrate concentration in water, experimental results demonstrate the usefulness of the e-FBG sensor in measuring nitrate compounds in water with good sensitivity in the low concentration range of 0–40 ppm. The sensor is surface functionalized with polymer PMMA capable of detecting the pesticide Permethrin at a concentration of 3ppm.
- Theoretical results: The successfully manufactured e-FBG optical sensor probe makes an important contribution to promoting research and technology in manufacturing photonic sensors for food and environmental control in agriculture.
- Applied results: The optical device system includes the e-FBG optical sensor probe integrated in the fiber laser configuration, capable of practical applications for fast field detection of pesticide residues, pesticides or biochemical parameters in agricultural products.

Surface functionalized e-FBG sensor probe capable of detecting low concentrations of the pesticide Permethrin. The e-FBG probe is coupled in fiber-optic loop laser configuration to increase the sensitivity of the sensor to form an optical sensor system capable of being applied as sensors in the environment and food in agriculture.

- Patents (list):
Phạm Văn Hội, Bùi Huy, Phạm Thanh Bình, Nguyễn Thúy Vân, Đầu dò cảm biến sử dụng cách tử Bragg trong sợi quang ăn mòn một phần (e-FBG) có phủ lớp chức năng để nâng cao độ chọn lọc tác nhân cần đo và sử dụng được nhiều lần, Bằng sáng chế số 28193, cấp theo quyết định số: 5043w/QĐ-SHTT, ngày: 30/3/2021.
- Scientific papers in referred journals (list):
4.    Huy Bui, Thuy Van Nguyen, Thanh Son Pham, Van Hoi Pham and Thanh Binh Pham, High enhancement factor of SERS probe based on silver nano-structures deposited on a silica microsphere by laser-assisted photochemical method, Meas. Sci. Technol. 32, 025109 (6pp), 2021.
5.    Phạm Thanh Bình, Nguyễn Thúy Vân, Trần Thị Châm, Phạm Nam Thắng, Vũ Đức Chính, Bùi Huy và Phạm Văn Hội, Nghiên cứu chế tạo đầu dò cảm biến hóa-sinh trên nền cách tử Bragg quang sợi cấu trúc D-form, Tuyển tập báo cáo của Hội nghị Vật lý Chất rắn và Khoa học Vật liệu Toàn quốc lần thứ 11– SPMS 2019, pp. 403-408, 2019.
6.    Pham Thanh Binh, Bui Huy, Nguyen Thuy Van, Tran Thi Cham, Dang Duc Toan, Do Thuy Chi, Bui Thi Trang, Nguyen Anh Tuan and Pham Van Hoi, Control of the structure and density of silver nanoparticles on an optical fiber core obtained by laser-induced surfactantless photochemical deposition, Tuyển tập báo cáo của Hội nghị Vật lý Chất rắn và Khoa học Vật liệu Toàn quốc lần thứ 11– SPMS 2019, pp. 409-411, 2019.
- Technological products (describe in details: technical characteristics, place): - The e-FBG sensor probe is fabricated by using two methods: chemical etching and mechanical abrasion method, capable of identifying some toxic organic substances dissolved in water at low concentrations. The surface functionalized e-FBG sensor probe uses a polymer capable of detecting the pesticide Permethrin at a concentration of 3ppm. The e-FBG sensor probe is kept at the Laboratory - Department of Optical Fiber Materials and Applications, Institute of Materials Science.