Algal polysaccharides on lipid Langmuir–Blodgett films and molecular effects upon metal ion contact

Brito, Audrey Kalinouski de; Caseli, Luciano; Nordi, Cristina Souza Freire

doi:10.1016/j.tsf.2013.02.009

Cited by 8 publications

(7 citation statements)

References 31 publications

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“…The strong presence of the amide II band indicates the presence of protein. [79][80][81] The amide II region is commonly present with the amide I peak, but is overlapping with our OH bend mode and not discernable. Current work is underway to utilize the low frequency IRRAS spectra for specific chemical identification.…”

Section: Organic Partitioning To the Aqueous Surface Using Infrared Rmentioning

confidence: 78%

The Ocean’s Elevator: Evolution of the Air-Seawater Interface During a Small-Scale Algal Bloom

Rogers¹,

Neal²,

Saha³

et al. 2020

Preprint

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We explore in situ the surface properties of marine algal blooms of diatom monocultures by utilizing surface techniques of Brewster angle microscopy (BAM) imaging, vibrational sum frequency generation spectroscopy (SFG), and infrared reflection absorption spectroscopy (IRRAS). Over the course of the bloom, the marine algae produce surface-active biogenic molecules that temporally partition to the topmost interfacial layers and are selectively probed through surface imaging and spectroscopic measurements. BAM images show morphological structural changes and heterogeneity in the interfacial films with increasing density of surface-active biogenic molecules. Film thickness calculations quantified the average surface thickness over time. The image results reveal an ~5 nm thick surface region in the late stages of the bloom which correlates to typical sea surface nanolayer thicknesses. Our surface-specific SFG spectroscopy results show significant diminishing in the intensity of the dangling OH bond of surface water molecules consistent with organic molecules partitioning and replacing water at the air-seawater interface as the algal bloom progresses. Interestingly, we observe a new broad peak appear between 3500 cm<sup>-1</sup> to 3600 cm<sup>-1</sup> in the late stages of the bloom that is attributed to weak hydrogen bonding interactions of water to the surface-active biogenic matter. IRRAS confirms the presence of organic molecules at the surface as we observe increasing intensity of vibrational alkyl modes and the appearance of a proteinaceous amide band. Our work shows the often overlooked but vast potential of tracking changes in the interfacial regime of small-scale laboratory marine algal blooms. By coupling surface imaging and vibrational spectroscopies to complex, time-evolving, marine-relevant systems, we provide additional insight into unraveling the temporal complexity of sea spray aerosol compositions.

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Section: Organic Partitioning To the Aqueous Surface Using Infrared Rmentioning

confidence: 78%

The Ocean’s Elevator: Evolution of the Air-Seawater Interface During a Small-Scale Algal Bloom

Rogers¹,

Neal²,

Saha³

et al. 2020

Preprint

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show abstract

“…This result is expected because homogeneous patterns are more common for LB films originated from pure lipid monolayers. 16,24 As we have macromolecules (polysaccharides, enzyme, and CNT) transferred from the aqueous subphase, we did not expect a homogeneous distribution. 11,24 Simple impregnation of these components by means of, for instance, the drop-casting method, could lead to relatively more heterogeneous and thicker films.…”

Section: Resultsmentioning

confidence: 98%

Carbon Nanotubes and Algal Polysaccharides To Enhance the Enzymatic Properties of Urease in Lipid Langmuir–Blodgett Films

et al. 2018

Self Cite

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Algal polysaccharides (extracellular polysaccharides) and carbon nanotubes (CNTs) were adsorbed on dioctadecyldimethylammonium bromide Langmuir monolayers to serve as a matrix for the incorporation of urease. The physicochemical properties of the supramolecular system as a monolayer at the air-water interface were investigated by surface pressure-area isotherms, surface potential-area isotherms, interfacial shear rheology, vibrational spectroscopy, and Brewster angle microscopy. The floating monolayers were transferred to hydrophilic solid supports, quartz, mica, or capacitive electrolyte-insulator-semiconductor (EIS) devices, through the Langmuir-Blodgett (LB) technique, forming mixed films, which were investigated by quartz crystal microbalance, fluorescence spectroscopy, and field emission gun scanning electron microscopy. The enzyme activity was studied with UV-vis spectroscopy, and the feasibility of the thin film as a urea sensor was essayed in an EIS sensor device. The presence of CNT in the enzyme-lipid LB film not only tuned the catalytic activity of urease but also helped to conserve its enzyme activity. Viability as a urease sensor was demonstrated with capacitance-voltage and constant capacitance measurements, exhibiting regular and distinctive output signals over all concentrations used in this work. These results are related to the synergism between the compounds on the active layer, leading to a surface morphology that allowed fast analyte diffusion owing to an adequate molecular accommodation, which also preserved the urease activity. This work demonstrates the feasibility of employing LB films composed of lipids, CNT, algal polysaccharides, and enzymes as EIS devices for biosensing applications.

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“…In the late stage of the bloom, the negative peak at ∼1451 cm –1 is assigned to the CH 2 scissoring (δ CH 2 ) and the negative band at ∼1534 cm –1 is assigned to the amide II region. The strong presence of the amide II band indicates the presence of protein. − The amide II region is commonly present with the amide I peak (∼1651 cm –1 ) but is overlapping with our OH bend mode (∼1660 cm –1 ) and not resolvable. Current work is underway to utilize the low-frequency IRRAS spectra for specific chemical identification.…”

Section: Resultsmentioning

confidence: 99%

The Ocean’s Elevator: Evolution of the Air–Seawater Interface during a Small-Scale Algal Bloom

Rogers

Neal

Saha

et al. 2020

ACS Earth Space Chem.

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The composition and lifetime of sea spray aerosols are driven by the molecular and biological complexity of the air−seawater interface. We explore in situ the surface properties of marine algal bloom diatom monocultures by utilizing surface techniques of Brewster angle microscopy (BAM) imaging, vibrational sum-frequency generation (SFG) spectroscopy, and infrared reflection−absorption spectroscopy (IRRAS). Over the course of the bloom, the marine algae produce surface-active biogenic molecules that temporally partition to the topmost interfacial layers and are selectively probed through surface imaging and spectroscopic measurements. BAM images show morphological structural changes and heterogeneity in the interfacial films with increasing density of surface-active biogenic molecules. Film thickness calculations quantified the average surface thickness of a productive bloom over time. The image results reveal an ∼5 nm thick surface region in the late stages of the bloom, which correlates with typical sea surface nanolayer thicknesses. Our surface-specific SFG spectroscopy results show significant diminishing in the intensity of the dangling OH bond of surface water molecules consistent with organic molecules partitioning and replacing water at the air−seawater interface as the algal bloom progresses. Interestingly, we observe a new broad band appear between 3500 and 3600 cm −1 in the late stages of the bloom that is attributed to weak hydrogen bonding interactions of water to the surface-active biogenic matter. IRRAS confirms the presence of organic molecules at the surface as we observe an increasing intensity of vibrational alkyl modes and the appearance of a proteinaceous amide band over time. Our work shows the often overlooked but vast potential of tracking changes in the interfacial regime of small-scale laboratory marine algal blooms. By coupling surface imaging and vibrational spectroscopies to complex, time-evolving, marine-relevant systems, we provide additional insight into unraveling the temporal complexity of sea spray aerosol compositions.

show abstract

Algal polysaccharides on lipid Langmuir–Blodgett films and molecular effects upon metal ion contact

Cited by 8 publications

References 31 publications

The Ocean’s Elevator: Evolution of the Air-Seawater Interface During a Small-Scale Algal Bloom

The Ocean’s Elevator: Evolution of the Air-Seawater Interface During a Small-Scale Algal Bloom

Carbon Nanotubes and Algal Polysaccharides To Enhance the Enzymatic Properties of Urease in Lipid Langmuir–Blodgett Films

The Ocean’s Elevator: Evolution of the Air–Seawater Interface during a Small-Scale Algal Bloom

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