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Single-walled carbon nanotubes (SWCNTs) emit near-infrared (NIR) fluorescence that is ideal for optical sensing. However, the low quantum yields diminish the sensor’s signal-to-noise ratio and limits the penetration depths for in vivo measurements. In this study, we perform a systematic investigation of the plasmonic effects of Ag and Au nanoparticles of various geometries to tune and even enhance the fluorescence intensity of single-stranded DNA-wrapped SWCNTs (ssDNA-SWCNTs). We observe a chirality-dependent NIR fluorescence enhancement that varies with both nanoparticle shape and material, with Au nanorods increasing (7, 5) and (7, 6) chirality emissions by 80% and 60% and Ag nanotriangles increasing (7, 5) and (6, 5) emissions by 200% and 240%, respectively. The chirality-dependent enhancement was modeled using finite element modeling (FEM), which confirms contributions not only from a plasmon-induced localized increase in electron density but also from the radiative recombination of dark exciton states from the resulting electromagnetic field. Finally, we demonstrate the application of these nanoparticles in enhancing the single-molecule fluorescence of individual SWCNTs imaged in a custom-built confocal setup. The plasmonically coupled sensors show four orders of magnitude greater sensitivity towards ferricyanide, a model analyte, compared to the non-coupled sensors. Plasmonic nanoparticles thus provide a tunable means of modulating SWCNT fluorescence to study fundamental transitions of otherwise forbidden states and to improve the optical sensing performance.

Cells can take up nanoscale materials, which has important implications for understanding cellular functions, biocompatibility as well as biomedical applications. Controlled uptake, transport and triggered release of nanoscale cargo is one of the great challenges in biomedical applications of nanomaterials. Here, we study how human immune cells (neutrophilic granulocytes, neutrophils) take up nanomaterials and program them to release this cargo after a certain time period. For this purpose, we let neutrophils phagocytose DNA-functionalized single-walled carbon nanotubes (SWCNTs) in vitro that fluoresce in the near infrared (980 nm) and serve as sensors for small molecules. Cells still migrate, follow chemical gradients and respond to inflammatory signals after uptake of the cargo. To program release, we make use of neutrophil extracellular trap formation (NETosis), a novel cell death mechanism that leads to chromatin swelling, subsequent rupture of the cellular membrane and release of the cell's whole content. By using the process of NETosis, we can program the time point of cargo release via the initial concentration of stimuli such as phorbol 12-myristate-13-acetate (PMA) or lipopolysaccharide (LPS). At intermediate stimulation, cells continue to migrate, follow gradients and surface cues for around 30 minutes and up to several hundred micrometers until they stop and release the SWCNTs. The transported and released SWCNT sensors are still functional as shown by subsequent detection of the neurotransmitter dopamine and reactive oxygen species (H2O2). In summary, we hijack a biological process (NETosis) and demonstrate how neutrophils transport and release functional nanomaterials.

O-linked glycosylation, the greatest form of post-translational modifications, plays a key role in regulating the majority of physiological processes. It is, therefore, not surprising that abnormal O-linked glycosylation has been related to several human diseases. Recently, GALNT2, which encodes the GalNAc-transferase 2 involved in the first step of O-linked glycosylation, has attracted great attention as a possible player in many highly prevalent human metabolic diseases, including atherogenic dyslipidemia, type 2 diabetes and obesity, all clustered on the common ground of insulin resistance. Data available both in human and animal models point to GALNT2 as a molecule that shapes the risk of the aforementioned abnormalities affecting diverse protein functions, which eventually cause clinically distinct phenotypes (a typical example of pleiotropism). Pathways linking GALNT2 to dyslipidemia and insulin resistance have been partly identified, while those for type 2 diabetes and obesity are yet to be understood. Here, we will provide a brief overview on the present knowledge on GALNT2 function and dysfunction and propose novel insights on the complex pathogenesis of the aforementioned metabolic diseases, which all impose a heavy burden for patients, their families and the entire society.

Microbial fuel cells and biophotovoltaics represent promising technologies for green bioelectricity generation. However, these devices suffer from low durability and efficiency that stem from their reliance on living organisms to act as catalysts. Such limitations can be overcome with augmented capabilities enabled by nanotechnology. This review presents an overview of the different nanomaterials used to enhance bioelectricity generation through improved light harvesting, extracellular electron transfer, and anode performance. The implementation of nanomaterials in whole-cell energy devices holds promise in developing bioelectrical devices that are suitable for industry.

Background/objectives: A better understanding of adipose tissue biology is crucial to tackle insulin resistance and eventually coronary heart disease and diabetes, leading causes of morbidity and mortality worldwide. GALNT2, a GalNAc-transferase, positively modulates insulin signaling in human liver cells by down-regulating ENPP1, an insulin signaling inhibitor. GALNT2 expression is increased in adipose tissue of obese as compared to that of non-obese individuals. Whether this association is secondary to a GALNT2-insulin sensitizing effect exerted also in adipocytes is unknown. We then investigated in mouse 3T3-L1 adipocytes the GALNT2 effect on adipogenesis, insulin signaling and expression levels of both Enpp1 and 72 adipogenesis-related genes. Methods: Stable over-expressing GALNT2 and GFP preadipocytes (T0) were generated. Adipogenesis was induced with (R+) or without (R−) rosiglitazone and investigated after 15 days (T15). Lipid accumulation (by Oil Red-O staining) and intracellular triglycerides (by fluorimetric assay) were measured. Lipid droplets (LD) measures were analyzed at confocal microscope. Gene expression was assessed by RT-PCR and insulin-induced insulin receptor (IR), IRS1, JNK and AKT phosphorylation by Western blot. Results: Lipid accumulation, triglycerides and LD measures progressively increased from T0 to T15R- and furthermore to T15R+. Such increases were significantly higher in GALNT2 than in GFP cells so that, as compared to T15R+GFP, T15R- GALNT2 cells showed similar (intracellular lipid and triglycerides accumulation) or even higher (LD measures, p < 0.01) values. In GALNT2 preadipocytes, insulin-induced IR, IRS1 and AKT activation was higher than that in GFP cells. GALNT2 effect was totally abolished during adipocyte maturation and completely reversed at late stage maturation. Such GALNT2 effect trajectory was paralleled by coordinated changes in the expression of Enpp1 and adipocyte-maturation key genes. Conclusions: GALNT2 is a novel modulator of adipogenesis and related cellular phenotypes, thus becoming a potential target for tackling the obesity epidemics and its devastating sequelae.

The internalization of fluorescent single-walled carbon nanotubes (SWCNTs) in photosynthetic microbes can be exploited for applications ranging from energy conversion and imaging to biomolecule delivery. The internalization of these nanoparticles are largely controlled by the permeability of the surrounding microbial cell walls, which vary in surface charge density, composition, thickness, and elasticity across different species of microbes. Since these properties play a critical role in controlling internalization, the extension of SWCNT-based technologies to prokaryotes thus requires a comparative assessment of uptake across different species. Herein, we extend a technology previously developed for internalizing SWCNTs in prokaryotes, specifically unicellular Synechocystis sp. PCC 6803, to Nostoc punctiforme, a filamentous cyanobacterial strain known to differentiate into heterocysts under nitrogen starvation. Heterocysts are specialized compartments within the filament that are capable of nitrogen fixation. These compartments possess cell walls that are distinct from vegetative cells, conferring heterocysts with relatively reduced permeability and increased resistance to mechanical and osmotic stress. Using a combination of near-infrared (NIR) fluorescence, scanning electron microscopy (SEM), and Raman spectroscopy, we investigate the effects of different cell-wall architectures and SWCNT functionalizations on internalization. We specifically examine the effects of these distinct SWCNT-cell interactions on long-term cell integrity, activity, and viability. We further show that local variations in membrane structure can dictate the extent of SWCNT association and uptake in Nostoc cells. This dependency of nanoparticle internalization on cell type can be exploited for the development of novel cell-specific staining and imaging technologies.

Properties of SWCNT-based sensors such as brightness and detection capabilities strongly depend on the characteristics of the wrapping used to suspend the nanotubes. In this study, we explore ways to modify the properties of DNA-SWCNT sensors by using chemically modified DNA sequences, with the aim of creating sensors more suitable for use in in vivo and in vitro applications. We show that both the fluorescence intensity and sensor reactivity are strongly impacted not only by the chemical modification of the DNA but also by the method of preparation. In the absence of modifications, the sensors prepared using MeOH-assisted surfactant exchange exhibited higher overall fluorescence compared to those prepared by direct sonication. However, we demonstrate that the incorporation of chemical modifications in the DNA sequence could be used to enhance the fluorescence intensity of sonicated samples. We attribute these improvements to both a change in dispersion efficiency as well as to a change in SWCNT chirality distribution.Furthermore, despite their higher intensities, the response capabilities of sensors prepared by MeOH-assisted surfactant exchange were shown to be significantly reduced compared to their sonicated counterparts. Sonicated sensors exhibited a globally higher turn-on response towards dopamine compared to the exchanged samples, with modified samples retaining their relative intensity enhancement. As the increases in fluorescence intensity were achieved without needing to alter the base sequence of the DNA wrapping or to add any exogenous compounds, these modifications can - in theory - be applied to nearly any DNA sequence to increase the brightness and penetration depths of a variety of DNA-SWCNT sensors without affecting biocompatibility or reducing the near-limitless sequence space available. This makes these sensors an attractive alternative for dopamine sensing in vitro and in vivo by enabling significantly higher penetration depths and shorter laser exposure times.

The unique combination of structural, optical, and electronic properties of nanocarbons (NCs) has made these materials particularly attractive for various applications in biotechnology and biomedicine, ranging from sensing, gene-delivery, bioimaging and therapeutics. When appropriately functionalized, NCs can overcome the cellular barriers of living organisms and localize within specific sub-cellular compartments, where they can then carry out different functions to sense, enhance, or complement natural cell function. Recent areas of research have focused on the targeted integration of engineered NCs into living photosynthetic organisms. The synergistic combination of NCs with plants and algae has the potential to impart photosynthetic organisms with improved capabilities, expanding their use for novel agricultural or electronic applications. This chapter will discuss the important milestones reached over the course of research into NC interactions with photosynthetic systems, highlighting the major applications in the field.

Context Type 2 diabetes (T2D) shows a high mortality rate, partly mediated by atherosclerotic plaque instability. Discovering novel biomarkers may help identify high-risk patients who would benefit from more aggressive and specific managements. We recently described a serum resistin and multicytokine inflammatory pathway (REMAP), including resistin, interleukin (IL)-1β, IL-6, IL-8, and TNF-α, that is associated with cardiovascular disease. Objective We investigated whether REMAP is associated with and improves the prediction of mortality in T2D. Methods A REMAP score was investigated in 3 cohorts comprising 1528 patients with T2D (409 incident deaths) and in 59 patients who underwent carotid endarterectomy (CEA; 24 deaths). Plaques were classified as unstable/stable according to the modified American Heart Association atherosclerosis classification. Results REMAP was associated with all-cause mortality in each cohort and in all 1528 individuals (fully adjusted hazard ratio [HR] for 1 SD increase = 1.34, P Conclusion REMAP is independently associated with and improves predict all-cause mortality in T2D; it can therefore be used to identify high-risk individuals to be targeted with more aggressive management. Whether REMAP can also identify patients who are more responsive to IL-6 and IL-1β monoclonal antibodies that reduce cardiovascular burden and total mortality is an intriguing possibility to be tested.

Single-walled carbon nanotubes (SWCNTs) demonstrate a unique combination of optical, chemical, and physical properties that render them suitable for a variety of sensing applications. Their photostable near-infrared (nIR) fluorescence emissions are highly sensitive to perturbations in the surrounding SWCNT environment, enabling optical sensors with single-molecule detection limits. Despite these immanent advantages, SWCNTs lack the inherent molecular recognition capabilities required for selective sensing applications. One approach to tuning sensor selectivity is to engineer synthetic and biological wrappings that cover the nanotube's surface in a manner that limits chemical access to the surface to specific target analytes. Among the numerous possible wrappings, deoxyribonucleic acid (DNA) has emerged as the most studied polymeric wrapping. In addition to the sequence-dependent tunability DNA offers in engineering selectivity, DNA assumes a peculiar helical wrapping conformation along the SWCNT surface that has been the focus of many experimental and computational studies. In this review, we summarize some of the major findings in the field, focusing on the underlying molecular interactions responsible for the conformational and molecular recognition elements of the wrapping. Special focus is given to characterizing the nucleotide binding affinity, DNA sequence dependency, DNA length variation, SWCNT chirality, and sugar backbone (RNA vs. DNA) contributions to the wrapping conformation and SWCNT fluorescence. This article concludes with an assessment of the latest DNA-SWCNT-based sensing platforms used for the selective, single- and multi-modal detection of target analytes.

The near-infrared emissions of single-walled carbon nanotubes (SWCNTs) falls within the optical transparency window of biological tissue, allowing deep-tissue, in vivo and in vitro imaging. However, the relatively low photoluminescence quantum yield of SWCNTs, which typically lies in the range of 0.1 - 1.5%, limits the penetration depth and sensitivity of these fluorophores when used as imaging agents and optical sensors. In the present work, we enhance the fluorescence emission of SWCNTs up to 10-fold by employing different localized surface plasmon resonance (LSPR) nanostructures. We observe a chirality-dependent enhancement that varies with the nanostructure geometry and material. The proposed mechanism is based on changes in the charge density following nanoparticle conjugation with the SWCNT. In agreement with this mechanism, the enhancement and quenching effects show a strong correlation with the distance between the SWCNTs and the nanostructures. Finally, we demonstrate the applicability of this technology in a single-molecule imaging SWCNT application.

Living photovoltaics represent a growing class of microbial devices that are based on whole cell-electrode interactions [1-3]. The limited charge transfer at the cell-electrode interface represents a significant bottleneck in realizing an efficient technology [4]. This study focuses on the development of poly(3,4-ethylenedioxythiophene) (PEDOT)-based electrodes with enhanced charge transfer properties at the interface [5,6]. This is accomplished by the electrosynthesis of PEDOT layers from aqueous sodium dodecyl sulfate (SDS) solutions. Potentiodynamic and potentiostatic electrochemical techniques, as well as scanning electron microscopy (SEM), atomic force microscopy (AFM), Raman spectroscopy, and theoretical modelling of the electropolymerization transient, were employed to assembly and characterize PEDOT electrodes under various conditions. The produced electrodes are able to capture photosynthetically derived current under multiple light-dark cycles when interfaced with Synechocystis sp. PCC 6803. In the presence of the Synechocystis, the PEDOT electrodes show a six-fold and two-fold enhancement over conventional graphite electrodes for both mediatorless and K3Fe(CN)6 mediated conditions, respectively. The ability of these electrodes to enhance extracted photocurrent for both direct and indirect electron transfer mechanisms provides a versatile platform for improving various microbial devices. [1] Zou, Y., Pisciotta, J., Billmyre, R. B., & Baskakov, I. V. (2009). Photosynthetic microbial fuel cells with positive light response. Biotechnology and Bioengineering, 104(5), 939-946. [2] Pisciotta, J. M., Zou, Y., & Baskakov, I. V. (2010). Light-dependent electrogenic activity of cyanobacteria. PloS one, 5(5), e10821. [3] Schuergers, N., Werlang, C., Ajo-Franklin, C. M., & Boghossian, A. A. (2017). A synthetic biology approach to engineering living photovoltaics. Energy & environmental science, 10(5), 1102-1115. [4] Mouhib, M., Antonucci, A., Reggente, M., Amirjani, A., Gillen, A. J., & Boghossian, A. A. (2019). Enhancing bioelectricity generation in microbial fuel cells and biophotovoltaics using nanomaterials. Nano Research, 1-16. [5] Tamburri, E., Orlanducci, S., Toschi, F., Terranova, M. L., & Passeri, D. (2009). Growth mechanisms, morphology, and electroactivity of PEDOT layers produced by electrochemical routes in aqueous medium. Synthetic metals, 159(5-6), 406-414. [6] Zajdel, T. J., Baruch, M., Méhes, G., Stavrinidou, E., Berggren, M., Maharbiz, M. M., ... & Ajo-Franklin, C. M. (2018). PEDOT: PSS-based multilayer bacterial-composite films for bioelectronics. Scientific reports, 8(1), 15293.

The exquisite structural and optical characteristics of single-walled carbon nanotubes (SWCNTs), combined with the tunable specificities of proteins and peptides, can be exploited to strongly benefit technologies with applications in fields ranging from biomedicine to industrial biocatalysis. The key to exploiting the synergism of these materials is designing protein/peptide-SWCNT conjugation schemes that preserve biomolecule activity while keeping the near-infrared optical and electronic properties of SWCNTs intact. Since sp2 bond-breaking disrupts the optoelectronic properties of SWCNTs, noncovalent conjugation strategies are needed to interface biomolecules to the nanotube surface for optical biosensing and delivery applications. An underlying understanding of the forces contributing to protein and peptide interaction with the nanotube is thus necessary to identify the appropriate conjugation design rules for specific applications. This article explores the molecular interactions that govern the adsorption of peptides and proteins on SWCNT surfaces, elucidating contributions from individual amino acids as well as secondary and tertiary protein structure and conformation. Various noncovalent conjugation strategies for immobilizing peptides, homopolypeptides, and soluble and membrane proteins on SWCNT surfaces are presented, highlighting studies focused on developing near-infrared optical sensors and molecular scaffolds for self-assembly and biochemical analysis. The analysis presented herein suggests that though direct adsorption of proteins and peptides onto SWCNTs can be principally applied to drug and gene delivery, in vivo imaging and targeting, or cancer therapy, nondirect conjugation strategies using artificial or natural membranes, polymers, or linker molecules are often better suited for biosensing applications that require conservation of biomolecular functionality or precise control of the biomolecule’s orientation. These design rules are intended to provide the reader with a rational approach to engineering biomolecule-SWCNT platforms, broadening the breadth and accessibility of both wild-type and engineered biomolecules for SWCNT-based applications.

In cells and tissues resistin affects IL-1β, IL-6, IL-8, IL-12 and TNF-α expression, thus suggesting the existence of a multi-cytokine “resistin pathway”. We investigated whether such pathway does exist in humans and, if so, if it is associated with cardiovascular risk factors and with major adverse cardiovascular events (MACE). Serum cytokines were measured in 280 healthy subjects from the Gargano Study 2 (GS2) whose BMI, waist circumference, HOMAIR, triglycerides, HDL-cholesterol, systolic and diastolic blood pressure data were available and in 353 patients with type 2 diabetes and coronary artery disease from the Gargano Heart Study (GHS)-prospective design (follow-up 5.4 ± 2.5 years; 71 MACE). In GS2, cytokines mRNA levels in white blood cells were also measured. In GS2, resistin mRNA was correlated with all cytokines expression (all p

In this work the possibility to exploit the ability of multiple scattering and localization of light shown by diatom silica shells (frustules) for photoluminescence amplification in a random laser was investigated. To this aim polymethylmethacrylate matrix composite random lasers based on rhodamine B and frustules as gain medium and scatterers, respectively, were prepared by solvent casting. Two different kinds of frustules were used, the first represented by diatomite, a fossil material composed of a mixture of frustules from different diatom species, without specific shape, size and porosity; the second were living diatom frustules from freshwater biofilm, a more homogeneous biosilica, dominated by one frustule type. Chemical properties, morphology and photoluminescence of both biosilica fillers were investigated. Random laser experiments were carried out on polymer composites. The diatomite material was characterised by rectangular and circular pores, ranging from 25 nm to 1 μm in size and showed weak photoluminescence upon excitation at 405 nm. Biofilm frustules were more homogeneous in size and microstructure, with average length of about 20 μm and pore diameters between 20 and 100 nm. The frustule photoluminescence, observed after irradiation at 488, 515, 543 and 635 nm was higher than in diatomite. In addition, the two biosilica materials differed with respect to the presence of superficial silanol groups, that were not detected in diatomite. Random laser experiments showed an incoherent random lasing effect in all polymer composites. The laser threshold diminished at increasing frustule content, with a lowest value recorded using biofilm frustules (308 kW cm−2). This is probably due to the frustule size exhibited in this almost monospecific biosilica, that was in the range of most typical morphology-dependent resonators.

The chemical and optical properties of single-walled carbon nanotubes (SWCNTs) have inspired the development of a plethora of different applications in the field of cell nanobiotechnology. However, most studies to date have focused on interfacing SWCNTs with cells of eukaryotic organisms. The work herein presented introduces a first comprehensive study focusing on the interaction of fluorescent SWCNTs with bacterial cells. We established wrappings that facilitate nanoparticle uptake over the bacterial cell wall, which represents a first important step towards the expansion of nanomaterials’ application in the broad field of microbiology. We employed a custom-built, spinning disc confocal microscope to image near-infrared (NIR) SWCNT fluorescence within the cells. By performing in situ cell growth and nanoparticle tracking we investigated the fate of internalized SWCNTs upon multiple cell division events. Real-time monitoring of cell growth revealed that the indefinitely photostable NIR fluorescence is inherited by daughter cells. The imparted NIR fluorescence thus offers an unprecedented avenue for quantitative and continuous imaging of nanobioengineered cells across multiple generations. Above and beyond bacterial nanobionics, this technique creates new opportunities for imaging subcellular targeting and trafficking of NIR-fluorescent probes in the field of drug delivery and biosensing.

The distinctive properties of single-walled carbon nanotubes (SWCNTs) have inspired the development of innovative applications in the field of cell nanobiotechnology. Most studies to date have focused on eukaryotic cells capable of internalizing SWCNTs functionalized with a variety of non-covalent wrappings. However, the effect of SWCNT functionalization on transport across the thick cell wall of prokaryotes remains unexplored. In this study, we explore the uptake of SWCNTs in Gram-negative cyanobacteria and demonstrate selective internalization of SWCNTs decorated with charged protein wrappings. The functionalized SWCNTs are shown to traverse the outer cell wall of both filamentous and unicellular strains of cyanobacteria, independent of whether the strain is naturally competent for DNA uptake, with adsorption and internalization rate constants of kads = (9.08 ± 0.16) x 10-8 s-1 and kin = (1.466 ± 0.011) x 10-4 s-1, respectively. A custom-built, spinning disc confocal microscope was used for the first time to directly image near-infrared (NIR) SWCNT fluorescence within cells, revealing a highly inhomogeneous distribution of SWCNTs that is otherwise overlooked using conventional NIR widefield imaging. The nanobionic cells show sustained photosynthetic activity and growth, offering a powerful avenue for engineering photosynthetic organisms with augmented and even inherited nanobionic capabilities.

Covalent functionalization of reduced graphene oxide (rGO) with the photosynthetic reaction center (RC) from Rhodobacter sphaeroides R26 via click chemistry reaction has been performed. The hybrid system was characterized by flash photolysis and infrared spectroscopy and the RC was found to retain its photoactivity and structural integrity. The strategy is applicable for the fabrication of hybrid bio-electronic devices capable of absorbing and converting solar energy.

Organic biological hybrid systems, accessible by covalent functionalization of photosynthetic proteins with molecular antennas, represent a promising novelty to enhance natural photosynthesis. In this paper, we present the successful bioconjugation of a commercial fluorophore, fluorescein isothiocyanate (FITC), to the photosynthetic reaction center RC from the bacterium Rhodobacter sphaeroides strain R26. The resulting hybrid outperforms the pristine protein in hole-electron couple generation yield, exclusively at wavelengths where the fluorophore absorbs while the protein does not.

For years, the distinctive optical and structural properties of single-walled carbon nanotubes (SWCNTs) have inspired the development of promising applications in the field of cell nanobiotechnology. In particular, the synergistic interaction of SWCNTs with photosynthetic organisms has the potential to enhance the native performance of biological machineries, paving the way for novel, renewable, and low cost solutions for light-harvesting, energy conversion, subcellular sensing, and DNA delivery. Recent studies have largely focused on enabling cellular uptake of SWCNTs by engineering the SWCNT surface through non-covalent side-wall functionalizations. Non-covalent functionalization with a rich variety of biomolecules and polymers has been shown to potentially increase SWCNT solubility and membrane translocation while endowing these nanostructures with enhanced biocompatibility. We performed a systematic investigation of the effect of SWCNT functionalization on membrane penetration properties using a novel biological host. A custom-built optical setup was used for the unprecedented characterization of near-infrared fluorescence emissions of internalized SWCNTs. These results were used to inform fuctionalization design rules for SWCNT internalization, and more broadly, present a versatile approach towards imaging internalized SWCNTs in biological systems.

The remarkable physicochemical properties of carbon nanomaterials make them promising candidates for biomedical and biotechnological applications. In particular, the distinctive optical and structural characteristics of single-walled carbon nanotubes (SWCNTs) have inspired the development of biologically applicable optical sensors and molecular delivery scaffolds1,2. Several studies have largely focused on enabling cell uptake of SWCNTs by engineering the SWCNT surface through non-covalent side-wall functionalizations. Non-covalent functionalization with a rich variety of biomolecules and polymers has been shown to potentially increase SWCNTs solubility and membrane translocation while endowing these nanostructures with enhanced biocompatibility3. These functionalizations have been engineered to permit SWCNT uptake by a variety of mammalian cells through both passive and energy-dependent pathways. Most recently, this platform was applied to intact chloroplasts to augment their photosynthetic capability in novel nanobionic devices4. Although factors such as cell type, functionalization zeta-potential, particle size, and membrane composition have been shown to affect uptake, these findings have largely relied on empirical approaches towards engineering uptake mechanisms5,6. Our work builds on these empirical findings to establish engineering design rules for enabling SWCNT-membrane interactions. We performed a systematic investigation of the effect of SWCNT functionalization on membrane penetration properties using a novel biological host. The results of this study were used to not only elucidate the underlying interaction on a molecular level, but also develop the first of a new generation of light-harvesting nanobionic devices. References: 1. Boghossian, A. a. et al. Near-infrared fluorescent sensors based on single-walled carbon nanotubes for life sciences applications. ChemSusChem 4, 848–863 (2011). 2. Oliveira, S. F. et al. Protein Functionalized Carbon Nanomaterials for Biomedical Applications. Carbon N. Y. (2015). 3. Vardharajula, S. et al. Functionalized carbon nanotubes: biomedical applications. Int. J. Nanomedicine 7, 5361–74 (2012). 4. Giraldo, J. P. et al. Plant nanobionics approach to augment photosynthesis and biochemical sensing. Nat. Mater. 13, 400–8 (2014). 5. Kostarelos, K. et al. Cellular uptake of functionalized carbon nanotubes is independent of functional group and cell type. Nat. Nanotechnol. 2, 108–113 (2007). 6. Holt, B. D., Dahl, K. N., Islam, M. F. & Al, H. E. T. Cells Take up and Recover from Nanotubes with Two Distinct Rates. 3481–3490 (2012)

Single-walled carbon nanotubes (SWCNTs) have unique optoelectronic properties that make them suitable for applications ranging from phototherapy to imaging and sensing, but their uptake has mainly been explored in eukaryotic cells. Here the authors explore the interaction of SWCNTs with cyanobacteria, showing that they are spontaneously taken up by cells only when coated with positive charges, opening the possibility of prokaryotic-based biotechnology applications. The distinctive properties of single-walled carbon nanotubes (SWCNTs) have inspired the development of many novel applications in the field of cell nanobiotechnology. However, studies thus far have not explored the effect of SWCNT functionalization on transport across the cell walls of prokaryotes. We explore the uptake of SWCNTs in Gram-negative cyanobacteria and demonstrate a passive length-dependent and selective internalization of SWCNTs decorated with positively charged biomolecules. We show that lysozyme-coated SWCNTs spontaneously penetrate the cell walls of a unicellular strain and a multicellular strain. A custom-built spinning-disc confocal microscope was used to image the distinct near-infrared SWCNT fluorescence within the autofluorescent cells, revealing a highly inhomogeneous distribution of SWCNTs. Real-time near-infrared monitoring of cell growth and division reveal that the SWCNTs are inherited by daughter cells. Moreover, these nanobionic living cells retained photosynthetic activity and showed an improved photo-exoelectrogenicity when incorporated into bioelectrochemical devices.

To date, the engineering of single-stranded DNA-SWCNT (DNA-SWCNT) optical biosensors have largely focused on creating sensors for new applications with little focus on optimising existing sensors for in vitro and in vivo conditions. Recent studies have shown that nanotube fluorescence can be severely impacted by changes in local cation concentrations. This is particularly problematic for neurotransmitter sensing applications as spatial and temporal fluctuations in the concentration of cations, such as Na+, K+, or Ca2+, play a central role in neuromodulation. This can lead to inaccuracies in the determination of neurotransmitter concentrations using DNA-SWCNT sensors, which limits their use for detecting and treating neurological diseases.Herein, we present new approaches using locked nucleic acid (LNA) to engineer SWCNT sensors with improved stability towards cation-induced fluorescence changes. By incorporating LNA bases into the (GT)15-DNA sequence, we create sensors that are not only more resistant towards undesirable fluorescence modulation in the presence of Ca2+ but that also retain their capabilities for the label-free detection of dopamine. The synthetic biology approach presented in this work therefore serves as a complementary means for enhancing nanotube optoelectronic behavior, unlocking previously unexplored possibilities for developing nano-bioengineered sensors with augmented capabilities.

Fluorescence microscopy in the second near-infrared optical window (NIR-II, 1000–1350 nm) has become a technique of choice for non-invasive in vivo imaging. The deep penetration of NIR light in living tissue, as well as negligible tissue autofluorescence within this optical range, offers increased resolution and contrast with even greater penetration depths. Here, we present a custom-built spinning-disc confocal laser microscope (SDCLM) that is specific to imaging in the NIR-II. The SDCLM achieves a lateral resolution of 0.5 ± 0.1 µm and an axial resolution of 0.6 ± 0.1 µm, showing a ~17% and ~45% enhancement in lateral and axial resolution, respectively, compared to the corresponding wide-field configuration. We furthermore showcase several applications that demonstrate the use of the SDCLM for in situ, spatiotemporal tracking of NIR particles and bioanalytes within both synthetic and biological systems.