Measurement of Ultralow Level Bioethanol Concentration for Production Using Evanescent Wave Based Optical Fiber Sensor

A Review of Optical Fibre Ethanol Sensors: Current State and Future Prospects

“…This change in absorption can manifest as a pure intensity change (no spectral modulation) or as a change in the transmitted light spectrum, e.g., through the appearance of dips or absorption edges in the received spectrum. Many geometrical deformations of optical fibres have been reported in the literature to enhance the sensitivity of absorbance-based ethanol sensors such as U-shaped, coil-shaped, meander-shaped and tapering sensors as well as a combination of bending and tapering sensors [ 35 , 41 , 54 , 55 , 56 ].…”

“…A Plastic Optical Fibre (POF) with 1 mm overall diameter was investigated for use as an ethanol concentration sensor by Memon et al [ 41 , 62 ]. A U-bent POF ethanol sensor for real-time sensing in biofuel production applications was designed as shown in Figure 4 a.…”

“…A specific example is evident in the case of bio-ethanol production using biomasses, specifically algae. There are very stringent requirements for specific sensitivity and resolution attainment, temperature stability and selectivity for sensing purposes as well as the ability to operate in real-time, which are crucial to avoiding sample loss and long lead time offline analysis [ 41 , 62 ]. It is clear that optical fibre sensors have a significant role to play in providing solutions in this scenario.…”

“…In general, these sensors have delivered encouraging results and demonstrated great potential for ethanol sensing in a wide range of applications. Figure 1 is a graphical summary of a selection of applications for ethanol sensing and optical fibre sensing schemes utilised for ethanol sensing extracted from recent literature [ 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 ] and includes sensor design parameters and typical output responses. Several articles have recently outlined and reflected on the advancement of optical fibre chemical and biosensors from various perspectives [ 31 , 32 , 44 , 45 , 46 , 47 , 48 ].…”

A Lamping U-Shaped Fiber Biosensor Detector for MicroRNA

“…U-shaped probes have been demonstrated to have a 10-fold improvement in absorbance sensitivity over straight probes [37]. The use of U-shaped optical fiber as chemical probes seems to be popular over the last two decades, with the fiber used in probes for various chemicals and features of chemicals, including benzene [38], ethanol [39][40][41], toluidine blue [42], pH levels [43], glucose [44,45], and salt [46], but few of studies as a biosensor especially in miRNA of cancer. The sensitive property of U-shaped optical fiber to the external environment is quite suitable for low-concentration bio-detectors analytics.…”