A facile method was developed to prepare a magnetic Ag nanocomposite. The 3-D nanofibrous structure of bacterial cellulose (BC) was homogenized with a ferric and ferrous mixture by a high speed blender. Magnetite nanoparticles were precipitated and incorporated into BC nanostructure by adjusting the homogenate to alkaline pH. The magnetic BC nanofiber soaked in dopamine solution will be coated with an adherent self-polymerized polydopamine layer. Since the polydopamine surface is very effective for reducing silver ion, Ag nanoparticles were incorporated into the dopamine treated magnetic BC by soaking in silver nitrate solution. The magnetization of the as-prepared Ag nanocomposite was well maintained. The magnetic Ag nanocomposite possesses a high antimicrobial activity against the model microbes Escherichia coli and Bacillus subtilis. It also has potential as a mild fermentation medium sterilizing agent that a freshly prepared LB medium shows no appreciable contamination after incubating with Ag nanocomposite for 4 h and removed by an external magnet.

The development of reliable and robust diagnostic tests is one of the most efficient methods to limit the spread of coronavirus disease 2019 (COVID-19), which is caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). However, most laboratory diagnostics for COVID-19, such as enzyme-linked immunosorbent assay (ELISA) and reverse transcriptase-polymerase chain reaction (RT-PCR), are expensive, time-consuming, and require highly trained professional operators. On the other hand, the lateral flow immunoassay (LFIA) is a simpler, cheaper device that can be operated by unskilled personnel easily. Unfortunately, the current technique has some limitations, mainly inaccuracy in detection. This review article aims to highlight recent advances in novel lateral flow technologies for detecting SARS-CoV-2 as well as innovative approaches to achieve highly sensitive and specific point-of-care testing. Lastly, we discuss future perspectives on how smartphones and Artificial Intelligence (AI) can be integrated to revolutionize disease detection as well as disease control and surveillance.

Surface functionalization of bacterial cellulose (BC) nanofibrils with aminated magnetite nanoparticles (MH) was carried out by one-pot solvothermal reaction of 1,6-hexanediamine, FeCl₃·6H₂O and BC pellicle in ethylene glycol at 200 °C for 6 h. The presence of amine surface-functionalized magnetite nanoparticles on the surface of cellulose nanofibrils not only significantly enhanced the thermal and mechanical properties but also the amine content of the nanostructured bacterial cellulose pellicle. Approximately 10.5 mmol g⁻¹ of amine was measured in the aminated magnetite-BC nanocomposite (BC@MH) which is about 14.3 fold higher than its counterpart (MH) prepared in the absence of BC pellicle. The never-dried BC@MH nanocomposite demonstrated a high adsorption capacity towards As(V) ions because of its high iron-oxide and amine content. Approximately 90 mg of As(V) can be adsorbed per gram of BC@MH.