hrvatski jezikClear Cookie - decide language by browser settings

Interaction of Silica Nanoparticles with Microalgal Extracellular Polymers

Vukosav, Petra; Pašalić, Lea; Bakarić, Danijela; Domazet Jurašin, Darija; Mišić Radić, Tea (2023) Interaction of Silica Nanoparticles with Microalgal Extracellular Polymers. Water, 15 (3). ISSN 2073-4441

PDF - Published Version - article
Available under License Creative Commons Attribution.

Download (2MB) | Preview


The properties of engineered nanoparticles (NPs) in the marine environment are influenced not only by the high ionic strength of seawater but also by the interaction of NPs with naturally occurring components of seawater, especially natural organic matter. The aim of this study was to investigate the interaction of engineered silica nanoparticles (SiO2 NPs, diameter of 12 nm) with microalgal extracellular polymers (EPS) released by the marine diatom Cylindrotheca closterium. Dissolved organic carbon (DOC) content of the prepared EPS suspension (200 μg mL−1) used throughout the study was 3.44 mg C L−1. The incorporation of individual SiO2 NPs (height range 10–15 nm) and their nanoscale aggregates (height up to 25 nm, length up to 600 nm) into the EPS network was visualized by atomic force microscopy (AFM), whereas their molecular-level interaction was unraveled by the change in the signal of the Si-O group in their FTIR spectra. AFM imaging of C. closterium cells taken directly from the culture spiked with SiO2 NPs (10 μg mL−1) revealed that the latter are bound to the EPS released around the cells, predominantly as single NPs (height range 10–15 nm). Since AFM and dynamic and electrophoretic light scattering results demonstrated that SiO2 NPs dispersed in seawater without EPS showed enhanced aggregation (aggregate diameter of 990 ± 170 nm) and a 2.7-fold lower absolute zeta potential value compared to that measured in ultrapure water, our findings suggest that the presence of EPS biopolymers alters the aggregation affinity of SiO2 NPs in the marine environment. This might be of outmost importance during microalgal blooms when increased EPS production is expected because EPS, by scavenging and stabilizing SiO2 NPs, could prolong the presence of NPs in the water column and pose a threat to marine biota.

Item Type: Article
Uncontrolled Keywords: atomic force microscopy ; dynamic light scattering ; extracellular polymers ; FTIR spectroscopy ; marine diatom Cylindrotheca closterium ; silica nanoparticles
Subjects: NATURAL SCIENCES > Chemistry
NATURAL SCIENCES > Interdisciplinary Natural Sciences > Marine Science
Divisions: Division for Marine and Enviromental Research
Project titleProject leaderProject codeProject type
Od površinskih svojstava stanica alga do pokazatelja stresa u vodenim ekosustavima-CELLSTRESSNadica Ivošević DeNardisIP-2018-01-5840HRZZ
Model demijelinizacije na molekulskoj skali pri fiziološkim i patološkim uvjetima-DEMYMOLSCALEDanijela BakarićUIP-2020-02-7669HRZZ
Depositing User: Tea Mišić Radić
Date Deposited: 06 Mar 2023 13:09
DOI: 10.3390/w15030519

Actions (login required)

View Item View Item


Downloads per month over past year

Increase Font
Decrease Font
Dyslexic Font