Key Technologies Of Microstructure Fiber Optic Sensing For Protein Molecule Detection

Chronic diseases,if not prevented and treated timely,will cause significant harm to human life and health.However,early diagnosis of many chronic diseases is challenging to achieve with traditional medical diagnostic devices alone.The main factor is that the high sensitivity characteristics of these medical devices usually conflict with convenient service,fast response,and low price.Optical fiber sensing technology is widely used in medical testing due to its low cost,high sensitivity,corrosion resistance,and in-line detection properties.This paper researches the critical technology of microstructured optical fiber sensing for protein molecules that can be used as markers of multiple chronic diseases.By combining high thermo-optical coefficient polymers and novel two-dimensional materials with photothermal detection technology,various high-performance sensor devices are realized for protein molecule concentration detection in multiple scenarios.This research lays the foundation for the early diagnosis of diseases and the application of online detection platforms.The main content of this paper includes:（1）Study of a label-free fiber optic sensor based on the photothermal effect of biomolecules,which detects myoglobin concentration in the urine.The sensor is tapered microfiber（TMF）coated with a high thermo-optical coefficient polymer.The results showed that the sensor’s sensitivity could reach-267.652 nm/（mg/m L）with a limit of detection（LOD）of 74.7 ng/m L and a response time of 30 s in the concentration range of 0.0001 to 0.10 mg/m L.（2）To study an optofluidic system based on the photothermal effect of hemoglobin molecules.Label-free measurement of hemoglobin concentration was achieved by a Knot-type micro-nano fiber ring resonant cavity encapsulated in polydimethylsiloxane（PDMS）.The sensitivity was 0.32 nm/（g/d L）,and the LOD was as low as 0.06 g/d L over a wide concentration interval of 8 g/d L to 16 g/d L.（3）To study a two-dimensional titanium carbide nitride（Ti₃CN-MXene）integrated long-period fiber grating detection device to detect total serum protein concentration.The results showed that the sensor achieved a detection limit of 0.101mg/m L in combination with the photothermal effect of total serum protein.It reduced the LOD by nearly an order of magnitude compared to the conventional.