State-of-the-Art and Next Generation Intra-Articular Implantable Biosensors for Osteoarthritis: From Analytical Limits to Operational Stability Abdullateef Gbolahan Olayiwola, Albina Abdossova, Daniele Tosi, Gorka Orive, Zhe Liu, Cevat Erisken Biosensors, 2026 Osteoarthritis (OA) and osteochondral degeneration present a significant clinical burden characterized by the complex interplay of extracellular matrix degradation and chronic inflammation. While biochemical profiling has matured, a critical translational gap remains in transitioning from benchtop assays to systems capable of continuous, intra-articular monitoring. This review provides a comprehensive synthesis of experimentally validated biosensing technologies, including optical, electrochemical, and piezoelectric Quartz Crystal Microbalance (QCM) platforms, evaluated through the lens of sensing architecture, biomarker specificity, and matrix compatibility. Our analysis reveals that while optical sensors offer superior sensitivity, electrochemical platforms show the greatest promise for miniaturized, implantable integration. However, a pivot in the field is identified: the primary bottleneck has shifted from analytical detection limits to operational stability within the hostile synovial environment. Current research is largely restricted to single-analyte detection in simplified media, failing to address the multifactorial nature of OA. We propose that the next generation of osteochondral diagnostics must prioritize multiplexed arrays, mechanically compliant architectures, and machine-learning-assisted signal processing. By bridging these engineering frontiers, biosensors will evolve from passive diagnostic tools into intelligent, personalized platforms for real-time disease management.
Surface-Modified Extrinsic Semi-Distributed Interferometers for Fiber-Optic Refractive Index Detection and Biosensing Albina Abdossova, Toheeb Olalekan Oladejo, Sabira Seipetdenova, Marzhan Nurlankyzy, Aigerim Omirzakova, Aidana Bissen, Aliya Bekmurzayeva, Carlo Molardi, Cevat Erisken, Wilfried Blanc, Daniele Tosi Biosensors, 2026 A semi-distributed interferometer is a low-reflectivity device with refractive index sensing capability, exploiting the random reflectivity of a nanoparticle-doped fiber to form a weak distributed cavity. In this work, we extend this concept to an extrinsic semi-distributed interferometer (ESDI), using an overlay made of polydimethylsiloxane (PDMS) around the fiber tip; this structure can then be surface-modified using a thin metallic film or a nanoparticle coating. We report gold-sputtered and gold-nanoparticle-coated ESDI structures for refractive index sensing capability, with the latter achieving superior performances with an average sensitivity of 62.8 dB/RIU (refractive index units) with resolution of 3.9 × 10−5 RIU over the range of 1.34790–1.35981. We also report a possible biological application using a biofunctionalized version of this probe for the detection of VEGF (vascular endothelial growth factor); the gold-sputtered probe achieves the highest sensitivity, 0.0565 dB for each 10× concentration increase, with 355 fM detection limit.
Hydrogels for Osteochondral Interface Regeneration: Biomaterial Types, Processes, and Animal Models Sanazar Kadyr, Bakhytbol Khumyrzakh, Swera Naz, Albina Abdossova, Bota Askarbek, Dilhan M. Kalyon, Zhe Liu, Cevat Erisken Gels, 2026 The osteochondral interface (OCI) is a structurally and functionally complex tissue whose degeneration or injury often results in poor healing and joint dysfunction due to its avascular and hypocellular nature. Conventional surgical treatments remain suboptimal, prompting growing interest in regenerative approaches, particularly with the utilization of hydrogel-based biomaterials that can mimic the extracellular matrix and support osteochondral regeneration. This study reviewed types of hydrogels, scaffold processing techniques, and animal models for OCI regeneration. Our search demonstrated that gelatin, alginate, chitosan, and hyaluronic acid were the most frequently investigated hydrogels. Layered constructs dominated current scaffold designs, while advanced methods such as 3D printing and extrusion demonstrated unique potential to create graded architectures resembling the native OCI. Rabbits were the most widely used in vivo models, though translation will require larger animal studies with clinically relevant defect sizes. Future efforts should focus on developing mechanically reinforced, biologically active, and continuously graded hydrogels, supported by standardized preclinical validation in large-animal models, to accelerate translation toward clinical solutions for osteochondral regeneration.
Detection of vaccinia virus proteins in wastewater environment using biofunctionalized optical fiber semi-distributed FBG-assisted interferometric probes Albina Abdossova, Aina Adilzhankyzy, Kuanysh Seitkamal, Massimo Olivero, Guido Perrone, Wilfried Blanc, Luca Vangelista, Daniele Tosi Sensing and Bio Sensing Research, 2024 In this work, we present the detection of proteins expressed by poxvirus with fiber-optic probes based on a semi-distributed interferometer (SDI) assisted by a fiber Bragg grating (FBG), performing the measurement directly into a wastewater sample. Modern biosafety applications benefit from real-time, dynamic-sensing technologies that can perform diagnostic tasks into a wide set of analytes, with a particular emphasis on wastewater, which appears to collect a significant number of viral titers in urban and indoor environments. The SDI/FBG probe can perform substantial progress in this field, as it embeds a dual sensitivity mechanism to refractive index changes (sensitivity up to 266.1 dB/RIU (refractive index units)) that can be exploited in biosensing, while simultaneously having the capability to measure the temperature (sensitivity 9.888 pm/°C), thus providing an intrinsic cross-sensitivity compensation. In addition, a standard FBG analyzer can be used as an interrogator, improving affordability and real-time detection over previous works. The probes have been functionalized with antibodies specific for L1, A27 and A33 vaccinia virus proteins, performing detection of a protein concentration in a scenario compatible with online viral threat detection. Direct detection of wastewater samples shows that the L1-functionalized sensor has a higher response, 9.1–11.3 times higher than A33 and A27, respectively, with a maximum response of up to 1.99 dB and excellent specificity. Dynamic detection in wastewater shows that the sensors have a response over multiple detection cycles, with a sensitivity of 0.024–0.153 dB for each 10-fold increase of concentration. • We present direct and online detection of proteins expressed by poxvirus. • Detection achieved through fiber-optic semi-distributed interferometer probes. • Dual detection of refractive index and temperature with high sensitivity. • Direct detection of L1, A27, A33 antibodies into wastewater is reported. • Real-time sensing demonstrated through cycles of sensing.
All-fiber label-free optical fiber biosensors: from modern technologies to current applications [Invited] Aliya Bekmurzayeva, Marzhan Nurlankyzy, Albina Abdossova, Zhuldyz Myrkhiyeva, Daniele Tosi Biomedical Optics Express, 2024 Biosensors are established as promising analytical tools for detecting various analytes important in biomedicine and environmental monitoring. Using fiber optic technology as a sensing element in biosensors offers low cost, high sensitivity, chemical inertness, and immunity to electromagnetic interference. Optical fiber sensors can be used in in vivo applications and multiplexed to detect several targets simultaneously. Certain configurations of optical fiber technology allow the detection of analytes in a label-free manner. This review aims to discuss recent advances in label-free optical fiber biosensors from a technological and application standpoint. First, modern technologies used to build label-free optical fiber-based sensors will be discussed. Then, current applications where these technologies are applied are elucidated. Namely, examples of detecting soluble cancer biomarkers, hormones, viruses, bacteria, and cells are presented.
Enhanced-backscattering optical fibers for inline interferometers: Applications to biosensing Daniele Tosi, Wilfried Blanc, Aliya Bekmurzayeva, Marzhan Nurlankyzy, Albina Abdossova, Sabira Seipetdenova, Kuanysh Seitkamal International Conference on Transparent Optical Networks, 2024 The interrogation of Rayleigh backscattering in single-mode optical fibers is a key asset for the development of distributed fiber-optic sensors operating in frequency- and time-domain. In order to increase the return signal, fibers with high backscattering have been introduced, exploiting weak random gratings or UV exposure; however the most viable method relies on introducing high doses or nanoparticles directly into the fiber core, which allows reaching scattering increments consistently over 50 dB. In this work, we discuss the use of such fibers for interferometry; exploiting its high backscattering, a short span of enhanced backscattering fiber can act as a random cavity, achieving a semi-stochastic spectrum that can be interrogated with a spectral analyzer. We present some of the recent applications in biosensing, including the detection of poxvirus proteins in wastewater and the detection of retinal biomarkers in tears.
