Medical Care Products Research Articles

Flexible B, N co-doped graphene electrodes for electrochemical detection of serotonin in bodily fluids

Real-time monitoring of neurotransmitters can offer critical information for understanding neural functions and diagnosing diseases. Herein, a flexible electrochemical biosensor suitable for detecting serotonin (5-HT) in different bodily fluids was developed based on vertical graphene co-doped with boron and nitrogen (BNVG). BNVG nanosheets were vertically grown on flexible tantalum substrates via chemical vapor deposition. The electrochemically active sites were regulated by changing the B and N contents in the BNVG film. The BNVG-based biosensor exhibited a quantitative response toward 5-HT in the pH range of 1.5–9.0. The linear concentration range of 5-HT depends on the pH, with the widest measurable concentration ranging from 0.10 to 224.43 μM. The range of 5-HT detection limits (S/N = 3) was 0.009–0.266 μM. The BNVG-based biosensor detected 5-HT in gastric juice, intestinal juice, and blood samples with high sensitivity and stability. The well-designed flexible BNVG-biointerface is an effective biosensor platform for detecting the neurotransmitter 5-HT, which can aid the development of neural electrodes and medical-care products.

Superabsorbent materials from shellfish waste--a review.

Increasing global demand for improved absorbent materials for body fluids in disposable medical and personal-care articles creates an incentive for new basic research and development of efficient absorbent materials and systems with additional benefits such as biodegradability or certain biomedical functions. Highly absorbing materials based on polyelectrolyte polymers can absorb up to 50 grams of body fluid per gram of dry mass. Currently available synthetic superabsorbents are not biodegradable in landfills and do not offer any value-added functions to personal and medical-care products. Various academic and industrial research groups have put considerable amounts of effort and resources toward development of new absorbent materials from natural polymers, which would decompose in landfills. The basic substrates in these studies have been mainly polysaccharides, particularly cellulose and starch. The most common approach has involved converting these polymers into carboxymethyl derivatives followed by structural cross-linking. Commercial synthetic superabsorbent polymers as well as those derived from cellulose and starch are essentially polyanionic. On the other hand, polycationic absorbers seem to have potential functional advantages over the polyanionic counterparts. Chitin is the second abundant natural polymer, whose main derivative, chitosan, becomes polycationic in acid media. Currently, the main source of this polysaccharide is shellfish waste. This review provides basic information about new superabsorbent materials based on chitosan salts, their properties and preparation.