Cellulose nanofibers and graphene oxide are used to fabricate an electrochemical biosensor based on acetylcholinesterase for detecting organophosphates. This biosensor is simple and reliable, and it utilizes chlorpyrifos as a representative sample of highly dangerous OPs.

Gallic Acid Enhancement of Gold Nanoparticle Anticancer Activity in Cervical Cancer Cells Cervical cancer cells;gallic acid;apoptosis;gold nanoparticles; Cervical cancer (CxCa) is the most common cancer in women and a prominent cause of cancer mortality worldwide. The primary cause of CxCa is human papillomavirus (HPV). Radiation therapy and chemotherapy have been used as standard treatments, but they have undesirable side effects for patients. It was reported that gallic acid has antioxidant, antimicrobial, and anticancer activities. Gold nanoparticles are currently being used in medicine as biosensors and drug delivery agents. This study aimed to develop a drug delivery agent using gold nanoparticles conjugated with gallic acid. The study was performed in uninfected (C33A) cervical cancer cells, cervical cancer cells infected with HPV type 16 (CaSki) or 18 (HeLa), and normal Vero kidney cells. The results showed that GA inhibited the proliferation of cancer cells by inducing apoptosis. To enhance the efficacy of this anticancer activity, 15-nm spherical gold nanoparticles (GNPs) were used to deliver GA to cancer cells. The GNPs-GA complex had a reduced ability compared to unmodified GA to inhibit the growth of CxCa cells. It was interesting that high-concentration ($150{\mu}M$) GNPs-GA was not toxic to normal cells, whereas GA alone was cytotoxic. In conclusion, GNPs-GA could inhibit CxCa cell proliferation less efficiently than GA, but it was not cytotoxic to normal cells. Thus, gold nanoparticles have the potential to be used as phytochemical delivery agents for alternative cancer treatment to reduce the side effects of radiotherapy and chemotherapy.

Foodborne pathogens, including Plesiomonas shigelloides and Shigella flexneri B, are the major cause of diarrheal endemics worldwide. Antibiotic drug resistance is increasing. Therefore, bioactive compounds with antibacterial activity, such as gallic acid (GA), are needed. Gold nanoparticles (AuNPs) are used as drug delivery agents. This study aimed to conjugate and characterize AuNP–GA and to evaluate the antibacterial activity. AuNP was conjugated with GA, and the core–shell structures were characterized by small-angle X-ray scattering and transmission electron microscopy. Antibacterial activity of AuNP–GA against P. shigelloides and S. flexneri B was evaluated by well diffusion method. AuNP–GA bactericidal mechanism was elucidated by Fourier transform infrared microspectroscopic analysis. The results of small-angle X-ray scattering showed that AuNP–GA conjugation was successful. Antibacterial activity of GA against both bacteria was improved by conjugation with AuNP because the minimum inhibitory concentration value of AuNP–GA was significantly decreased (P<0.0001) compared to that of GA. Fourier transform infrared analysis revealed that AuNP–GA resulted in alterations of lipids, proteins, and nucleic acids at the bacterial cell membrane. Our findings show that AuNP–GA has potential for further application in biomedical sciences.

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