Artificial Receptor‐Based Optical Sensors (AROS): Ultra‐Sensitive Detection of Urea

Abstract

The combined approach of optical fiber interferometry with molecular imprinting technology has shown a tremendous potential for developing a specific and sophisticated bio‐detection system with high degree of resolution and sensitivity. However, the specificity limitation of the fiber optic sensors renders them unsuitable for several key applications. Molecular imprinted polymer (MIP), an indispensable artificial molecular receptor with a complementary structure and functionality for the target analyte, possesses the ability to overcome the limitations of specificity. Therefore, a new class of artificial receptor‐based optical sensors (AROS) constructed from an optical fiber interferometer integrated with artificial MIP for selective and ultrasensitive sensing of urea is demonstrated. The sensor device shows an unprecedented sensitivity of 0.584 × 1011 nm m −1 and a lower detection limit of 17.1 fM with a wide dynamic range of 10−11–10−4 m. This demonstration of an ultrasensitive, selective, and accurate AROS system is bound to find potential applications that requires remote sensing in harsh environmental conditions with large fluctuations in the temperature, pressure, and humidity.