Glucose-Sensitive Holographic (Bio)Sensors: Fundamentals and Applications

Nowadays sensors and especially biosensors play an important role in medical diagnosis and detection of food and environment contaminations. Biosensors’ facilities have been improved significantly by using technologies such as surface plasmon resonance, microfluidics, laser, and electrochemistry. These technologies are now available on chips in micro- and nano-scale and are capable of measuring the quantity of more than one analyte at once. One branch of these sensors is the holographic (bio)sensor. Reflection holographic sensors, which are optical devices fabricated based on Bragg’s law, can diffract light with specific wavelength as they absorb or release special ions or molecule depending on their polymer structure. Their action is reversible and rapid and by measuring the color change, it is possible to determine the concentrations in real-time. Reversibility let the operator use a sensor several times. There are many sensors designed for measuring ethanol, metal ions, enzymes activity, and glucose.