abstract
AimsThe objective of this work was to assess the antibacterial effect of 2-mercaptobenzothiazole (MBT), used as model-biocide, immobilized in a layered double hydroxide (LDH) structure, under different conditions of pH and salinity, envisaging possible applications of the system in active antifouling and anticorrosion coatings. Methods and ResultsBiological effects of MBT immobilized in LDH were assessed by monitoring bacterial bioluminescence of cell suspensions of either Allivibrio fischeri or a recombinant strain of Escherichia coli, as a proxy for bacterial activity. Salinity (1, 2 and 3% NaCl) and pH (4, 5, 6 and 7) of the suspension media were experimentally manipulated and biocide release tests were performed in parallel. The release profiles obtained by UV-visible spectrophotometry indicated a fast release of biocide from MBT@LDH, slightly enhanced in 3% NaCl and under alkaline conditions. However, biological effects were more pronounced at 1% NaCl and at neutral pH. ConclusionsThe release and toxic effect of MBT immobilized in LDH is dependent on the concentration of solutes in the suspension medium. Significance and Impact of the StudyThe results confirm LDH as a biologically compatible material with potential to be used for biocide delivery.
keywords
ESCHERICHIA-COLI; INTERCALATION; NANOCONTAINERS; NANOCAPSULES; TOXICITY; COATINGS
subject category
Biotechnology & Applied Microbiology; Microbiology
authors
Kuznetsova, A; Domingues, PM; Silva, T; Almeida, A; Zheludkevich, ML; Tedim, J; Ferreira, MGS; Cunha, A
our authors
Alena Kuznetsova
Research Fellowship
João Tedim
Associate Professor
Mário Guerreiro Silva Ferreira
Retired Professor
Mikhail Zheludkevich
Invited Principal Researcher
Patrícia Maia Domingues
PhD Student
Tiago Manuel Rodrigues da Silva
Collaboratoracknowledgements
Thanks are due to FCT for the financial support to CESAM (FCT UID/MAR/LA0017/2013) and CICECO - Aveiro Institute of Materials, POCI-01-0145-FEDER-007679 (FCT UID/CTM/50011/2013) and the Portuguese Foundation for Science and Technology (FCT) in the form of a PhD grant to Alena Kuznetsova (SFRH/BD/89490/2012) and Patricia M. Domingues (SFRH/BD/88162/2012).; This work was developed in the scope of the project CICECO-Aveiro Institute of Materials (ref. FCT UID/CTM/50011/2013), financed by national funds through the FCT/MEC and when applicable cofinanced by FEDER under the PT2020 Partnership Agreement. JoAo Tedim thanks FCT for the researcher grant IF/00347/2013. Thanks are due to Aleksey Lisenkov for SEM-EDS measurements.