TABLE 2.
Broad classification of biosensors and their advantages and limitations.
| Biosensor type | Target analyte | Detection principle | LOD | Linear range | Sample matrix type | Advantages | Limitations | Ref. |
|---|---|---|---|---|---|---|---|---|
| Electrochemical biosensors | ALT, AST, glucose, uric acid | Enzyme-catalyzed redox reactions producing measurable current or potential response | 2.97 U/L (for ALT) | 25–700 U/L (for ALT) | Plasma samples | • High sensitivity • Rapid response • Compatible with miniaturization and POC testing |
• Possible enzyme instability • Interference from biological matrices • Requires calibration |
Samy et al. (2023), Sun et al. (2023), Alatzoglou et al. (2024) |
| Optical biosensors | CK-18, adiponectin, IL-6, TNF-α, ROS | Changes in absorbance, fluorescence, or plasmon resonance upon target binding | 3.0 × 10−16 g/mL (for glucose); 0.13 μg/mL (for TNF-α) | 10−15 to 10−6 g/mL (for glucose); 100–1,500 ng/mL (for TNF-α) | Serum samples | • Label-free or label-based detection • Real-time monitoring • High specificity |
• Complex optical setups • Sensitive to environmental fluctuations • May require signal amplification |
Rajeev et al. (2018), Kaur et al. (2022), Kim et al. (2022), Lin and Tan (2023), Sojdeh et al. (2024) |
| CRISPR/Cas-based biosensors | Circulating nucleic acids (miR-122, miR-34a, miR-192), inflammation-related genes | Target recognition by guide RNA-Cas complex leading to collateral cleavage and fluorescent or colorimetric signal | - | - | Buffer samples | • High specificity • Programmable detection of genetic markers • Amenable to low-cost platforms |
• Requires nucleic acid extraction • Limited validation in clinical samples • Reagent storage stability issues |
Zhuang et al. (2022), Kumaran et al. (2023), Zhou et al. (2024) |
| Nanomaterial-based biosensors | Oxidative stress markers, lipid metabolites, and liver enzyme substrates | Signal amplification via catalytic or plasmonic activity of nanomaterials (like AuNPs, CeO2, CNTs) | 10 ng/mL (for 8-OHdG) | 10 μg/mL to 100 μg/mL (for 8-OHdG) | Saliva and urine samples | • Enhanced sensitivity and stability • Adaptable to multiple analytes • Cost-effective fabrication |
• Complex synthesis and reproducibility issues • Potential cytotoxicity of nanomaterials |
Sondhi et al. (2020), Bai and Li (2023), Zhu et al. (2024) |
| Microfluidic-based biosensors | ALT, AST, CK-18, glucose, lactate, cytokines | Integrated microchannels enabling multiplexed biochemical assays with minimal sample volume | 0–200 μM (for glucose); 1 to 10,000 pg mL–1 (for cytokines) | 30 µM (for glucose); 0.46–1.36 pg mL–1 (for cytokines) | Buffer | • High throughput • Minimal reagent use • Suitable for multi-analyte detection |
• Fabrication complexity • Potential biofouling • Limited clinical standardization |
Gao et al. (2021), Chinnappan et al. (2023), Lokar et al. (2023), Shi et al. (2023) |