Hydrogels are three‐dimensional water hungry networks that are currently the focus of intense scientific investigations owing to their potential applications in biomedicine, pharmaceuticals, biotechnology, biosensing, agriculture and cosmetics. Traditional hydrogels are incorporated with toxic cross‐linkers, lower drug loading and are shorter in load bearing capacity. Hydrogels demonstrate significant physiochemical modification in reaction to minor fluctuations in surrounding medium. Therefore, diverse cross‐linkers, polymer blending, modification in polymers/cross‐linkers and addition of reinforcement approaches are used. This review offers a comprehensive overview of application prospects of chitosan and carrageenan‐based hydrogel materials in biomedical sector. Initially, properties of hydrogels, their types, impact of natural‐synthetic polymer blending, requirement of filler and applications of hydrogels are summarized. Afterward, the applications of chitosan and carrageenan hydrogel platforms for drug delivery, tissue engineering, cosmetics, dentistry and ophthalmic treatment are thoroughly vetted. In conclusion, the extraordinary biocompatible, biodegradable and non‐toxic features of chitosan and carrageenan‐based hydrogel systems promote their applicability in biomedical fields.

The production of synthetic drugs is considered a huge milestone in the healthcare sector, transforming the overall health, aging, and lifestyle of the general population. Due to the surge in production and consumption, pharmaceutical drugs have emerged as potential environmental pollutants that are toxic with low biodegradability. Traditional chromatographic techniques in practice are time-consuming and expensive, despite good precision. Alternatively, electroanalytical techniques are recently identified to be selective, rapid, sensitive, and easier for drug detection. Metal–organic frameworks (MOFs) are known for their intrinsic porous nature, high surface area, and diversity in structural design that provides credible drug-sensing capacities. Long-term reusability and maintaining chemo-structural integrity are major challenges that are countered by ligand–metal combinations, optimization of synthetic conditions, functionalization, and direct MOFs growth over the electrode surface. Moreover, chemical instability and lower conductivities limited the mass commercialization of MOF-based materials in the fields of biosensing, imaging, drug release, therapeutics, and clinical diagnostics. This review is dedicated to analyzing the various combinations of MOFs used for electrochemical detection of pharmaceutical drugs, comprising antibiotics, analgesics, anticancer, antituberculosis, and veterinary drugs. Furthermore, the relationship between the composition, morphology and structural properties of MOFs with their detection capabilities for each drug species is elucidated.

Modern world is searching for water efficient agriculture techniques as irrigation is becoming scarce. Limited water resources and more food demand are the two key challenges in agriculture. Hydrogels which can respond intelligently by pH, temperature, light, ionic strength, osmotic pressure, magnetic or electric field changes are termed as intelligent or smart hydrogels which are analogous to conventional hydrogels in preparatory methods and features. Lag phase, constant release and decay phase are three steps involved in release of nutrients from polymeric hydrogels. In fact, hydrogels act as little reservoirs of water and dissolve nutrients that are released in controlled manner anchored by plant roots via capillary action. Hydrogels also sustain optimum amount of water in water stress conditions and reabsorb water in moist conditions which ultimately increases seedling, seed germination, plant growth and crop yield. Fertilizer and salt release are majorly dependent upon pH and temperature followed by diffusion‐controlled mechanism. Cross‐linkers, binders and fillers play pivotal role in determining properties, architecture and hydrogel pores. In comparison to potassium (K+) and phosphate (PO4−3) ions, nitrates (NO3−1) and ammonium (NH4+1) ions exhibited faster release rate. This review spotlights application prospects of three dimensional hydrogel in agriculture. Initially, properties of hydrogels, their classification, preparatory methods, effect of natural‐synthetic‐polymer blending and role of fillers are stated. Afterward, hydrogel functioning, significance, advantages, mechanism of fertilizer release and agriculture specific applications of hydrogels are comprehensively described. In conclusion, extraordinary biocompatible, cheaper, stable, biodegradable, durable, non‐toxic and re‐wettable characteristics of hydrogel systems motivated their utilization in agronomical applications.

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