/pdf/advances-in-novel-nanomaterial-based-optical-fiber-1a9r57cl.pdf

Advances in Novel Nanomaterial-Based Optical Fiber Biosensors—A Review

Glucose, an essential nutrient to the metabolism of organisms, is closely related to human health. Here, a novel serial quadruple tapered structure-based localized surface plasmon resonance (LSPR) sensor is employed to achieve accurate detection of glucose level in the human body. Gold nanoparticles (AuNPs) are immobilized on the serial quadruple taper fiber (SQTF) to induce LSPR. Furthermore, graphene oxide (GO) and multi-wall carbon nanotubes (MWCNTs) are used to increase the binding sites of enzymes to improve the sensing performance of probe. In our work, the SQTF probe surface is functionalized with glucose oxidase (GOx) enzyme to enhance selectivity. The sensitivity and limit of detection (LOD) of functionalized probe structure are 1.04 nm/mM and 0.24 mM over a linear range of 0 mM to10 mM, respectively. In addition, the reusability, reproducibility, stability and selectivity of SQTF probe are assessed to demonstrate the potential in measuring glucose content in the human body. 

Graphene Oxide/Multiwalled Carbon Nanotubes Assisted Serial Quadruple Tapered Structure-Based LSPR Sensor for Glucose Detection

Surface Plasmon Resonance (SPR) techniques are highly accurate in detecting biomolecular like blood group measurement, food adulteration, milk adulteration and recently developing as a rapid detection for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. In order to validate the clinical diagnosis, Real-time reverse transcriptase–polymerase chain reaction (RT-PCR) of nasopharyngeal swabs has been utilized, which is time consuming and expensive. For fast and accurate detection of the SARS-CoV-2 virus, SPR based biosensing chips are described in this review article. SPR sensors have the potential to be employed for fast, accurate, and portable SARS-CoV-2 virus diagnosis. To combat the SARS-CoV-2 pandemic, there is considerable interest in creating innovative biosensors that are quick, reliable, and sensitive for COVID-19 diagnosis.

/pdf/spr-based-biosensing-chip-for-covid-19-diagnosis-a-review-3gxqqpbs.pdf

SPR Based Biosensing Chip for COVID-19 Diagnosis—A Review

Glucose, an essential nutrient to the metabolism of organisms, is closely related to human health. Here, a novel serial quadruple tapered structure-based localized surface plasmon resonance (LSPR) sensor is employed to achieve accurate detection of glucose level in the human body. Gold nanoparticles (AuNPs) are immobilized on the serial quadruple taper fiber (SQTF) to induce LSPR. Furthermore, graphene oxide (GO) and multi-wall carbon nanotubes (MWCNTs) are used to increase the binding sites of enzymes to improve the sensing performance of probe. In our work, the SQTF probe surface is functionalized with glucose oxidase (GOx) enzyme to enhance selectivity. The sensitivity and limit of detection (LOD) of functionalized probe structure are 1.04 nm/mM and 0.24 mM over a linear range of 0 mM to10 mM, respectively. In addition, the reusability, reproducibility, stability and selectivity of SQTF probe are assessed to demonstrate the potential in measuring glucose content in the human body.

/pdf/novel-optical-fiber-based-structures-for-plasmonics-sensors-ri9n5vuk.pdf

Novel Optical Fiber-Based Structures for Plasmonics Sensors

Measuring cortisol levels as a stress biomarker is essential in many medical conditions associated with a high risk of metabolic syndromes such as anxiety and cardiovascular diseases, among others. One technology that has a growing interest in recent years is fiber optic biosensors that enable ultrasensitive cortisol detection. Such interest is allied with progress being achieved in basic interrogation, accuracy improvements, and novel applications. The development of improved cortisol monitoring, with a simplified manufacturing process, high reproducibility, and low cost, are challenges that these sensing mechanisms still face, and for which solutions are still needed. In this paper, a comprehensive characterization of a D-shaped fiber optic immunosensor for cortisol detection based on surface plasmon resonance (SPR) enabled by gold coating is reported. Specifically, the sensor instrumentation and fabrication processes are discussed in detail, and a simulation with its complete mathematical formalism is also presented. Moreover, experimental cortisol detection tests were performed for a detection range of 0.01 to 100 ng/mL, attaining a logarithmic sensitivity of 0.65 ± 0.02 nm/log(ng/mL) with a limit of detection (LOD) of 1.46 ng/mL. Additionally, an investigation of signal processing is also discussed, with the main issues addressed in order to highlight the best way to extract the sensing information from the spectra measured with a D-shaped sensor.

L. Silva

Papers

Label-free plasmonic immunosensor for cortisol detection in a D-shaped optical fiber.