In the present contribution, two nationwide surveys of personal protective equipment (PPE) pollution were conducted in Peru and Argentina aiming to provide valuable information regarding the abundance and distribution of PPE in coastal sites. Additionally, PPE items were recovered from the environment and analyzed by Fourier transformed infrared (FTIR) spectroscopy, Scanning electron microscopy (SEM) with Energy dispersive X-ray (EDX), and X-ray diffraction (XRD), and compared to brand-new PPE in order to investigate the chemical and structural degradation of PPE in the environment. PPE density (PPE m −2 ) found in both countries were comparable to previous studies. FTIR analysis revealed multiple polymer types comprising common PPE, mainly polypropylene, polyamide, polyethylene terephthalate, and polyester. SEM micrographs showed clear weathering signs, such as cracks, cavities, and rough surfaces in face masks and gloves. EDX elemental mapping revealed the presence of elemental additives, such as Ca in gloves and face masks and AgNPs as an antimicrobial agent. Other metals found on the surface of PPE were Mo, P, Ti, and Zn. XRD patterns displayed a notorious decrease in the crystallinity of polypropylene face masks, which could alter its interaction with external contaminants and stability. The next steps in this line of research were discussed.

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A sensor is a device that measures a physical quantity and converts it into a signal, which can be read by an observer or an instrument. It is composed of a receptor element that detects changes or events in a physical environment, and a transducer element that provides an output signal (Ummartyotin & Manuspiya, 2015). Biosensors incorporate biological elements that perform the recognition task. According to the IUPAC (Palchetti, Hansen, & Barcelo, 2017), a biosensor is an integrated receptor transducer device, capable of providing selective quantitative or semi-quantitative analytical information using a biological recognition element. The bioreceptor element of these biosensors may be enzymes, antibodies, living cells and tissue, among others. There are several advantages of biosensors over traditional sensors. Usually, the analyte detection carried out by biosensors can be made without prior separation. In addition, their short response times make possible the real-time monitoring of biological and manufacturing processes. Other advantages include their ease of use, allowing in-field or point-of-care measurements, the flexibility and simplicity of preparation, and the possibility of miniaturization and automatization (Cristea, Hârceagâ, & Sậndulescu, 2014). Miniaturization is of great importance because many biological samples are available in small amounts, and tissue damage must be minimized in cases of in vivo monitoring. The use of biosensors as components of modern medical devices has improved their portability, functionality and reliability for point-of-care analysis and real-time diagnosis (Morrison, Dokmeci, Demirci, & Khademhosseini, 2008).

Novel carrageenan micro- and nanogels were developed via a sonication-assisted microemulsion processing route. The diameter of the dry samples ranged 197.3 −421.35 nm whereas the diameter of the samples suspended in water ranged 467.8–605.9 nm. Hybrid κ/ι-carrageenan, rather than κ- or ι-carrageenan was used for the first time for the preparation of micro- and nanogels. KCl was used as a cross-linking agent and Tween 80 was used as surfactant. The micro- and nanogels suspended in water were found to simultaneously exhibit a lower diameter, and a lower swelling ratio with higher Tween 80 content. The micro- and nanogel suspension yields a zeta potential value of −50.5 mV, superior to values reported elsewhere for pure κ- or ι-carrageenan micro- and nanogels. The high stability was attributed to the high hydrophile-lipophile balance (HLB = 15) value of Tween 80. These results suggest that hybrid κ/ι-carrageenan micro- and nanogels are promising candidates for smart therapeutics applications.

Broadband Dielectric Relaxation Spectroscopy was performed to study the molecular dynamics of dried Bacterial Cellulose/Carboxymethyl Cellulose-Graphene Oxide (BC/CMC-GO) composites as a function of the concentration of CMC in the culture media. At low temperature the dielectric spectra are dominated by a dipolar process labelled as a β-relaxation, whereas electrode polarization and the contribution of dc-conductivity dominate the spectra at high temperatures and low frequency. The CMC concentration affects the morphological structure of cellulose and subsequently alters its physical properties. X-ray diffractometry measurements show that increasing the concentration of CMC promotes a decrease of the I/I ratio. This structural change in BC, that involves a variation in inter- and intramolecular interactions (hydrogen-bonding interactions), affects steeply their molecular dynamics. So, an increase of CMC concentration produces a significantly decrease of the β-relaxation strength and an increase of the dc-conductivity.