Modified Natural Rubber as a Simple Chemical Sensor with Smartphone Detection for Formaldehyde Content in a Seafood Sample.

A new biodegradable platform-based sensor for formaldehyde assay is proposed. Natural rubber latex was modified to polylactic acid-chloroacetated natural rubber polymer blend sheets. The polymer blend sheet was grafted using a water-based system with amine monomers as a platform, with a spot exhibiting positive polarity for immobilizing with anionic dye (Acid Red 27). The sensor was exposed to formaldehyde. The color intensity of the dye on the sensor spot would decrease. Using a smartphone with image processing (via ImageJ program), the color intensity change (∆B) could be followed. A linear calibration, ∆B intensity = 0.365 [FA] + 6.988, R2 = 0.997, was obtained for 10-150 mM FA with LOD and LOQ at 3 and 10 mM, respectively (linear regression method). The precision was lower than 20% RSD. Application to real seafood samples was demonstrated. The ready-to-use sensor with the proposed method was cost-effective, was portable for on-site analysis, and demonstrated green chemical analysis.

Biocompatibility and biodegradability of filler encapsulated chloroacetated natural rubber/polyvinyl alcohol nanofiber for wound dressing.

The novel biodegradable films of chloroacetated natural rubber/polyvinyl alcohol (CNR/PVA) (55/45 wt%) non-woven nanofiber films encapsulated with kaolin and starch (2.5 and 5 wt%) were produced successfully by green electrospinning technique. The effect of fillers with different content on the physical, chemical, mechanical, biocompatibility and biodegradation properties of CNR/PVA nanofiber films were investigated. The higher crystallinity obtained in CNR/PVA encapsulate with 2.5 wt% kaolin and nanofibers were formed with the maximum diameter distribution and mean value of 40-160 nm and 94.15 ±â€¯54.19 nm respectively. DSC and DMA revealed the kaolin can improve the interfacial adhesion between CNR and PVA and contribute to enhancing the chemical interactions. The mechanical properties improved upon encapsulation of starch and kaolin and more favourable nanofibers with smaller diameter obtained using kaolin rather than starch. The cytotoxicity results revealed the viability of the prepared nanofiber films with human dermal fibroblast cell. Furthermore, the incorporation of starch and kaolin accelerated the degradation rate and the highest enzymatic degradation obtained with 2.5 wt% of starch. The prepared nanofiber films have the potential to be applied for the skin tissue engineering scaffold applications.