Polystyrene Sulphonate Research Articles

THERMAL PROPERTIES OF PSS COATED COBALT ZINC FERRITE NANOPARTICLES SYNTHESIZED BY CO-PRECIPITATION METHOD

In this work Cobalt Zinc Ferrite nanoparticles Co1-xZnxFe2O4 for x = 0.25, 0.5 and 0.75 were synthesized via coprecipitation method. Annealing of all the samples was carried out at 700 ºC for 5 hours. To investigate the crystal structure XRD analysis was used which confirmed the ferrite structure of synthesized samples. Afterwards surface coating of all the samples was done by biocompatible polymer PSS. Surface functionalization of magnetic nanoparticles with PSS (Polystyrene Sulphonate) was confirmed by FTIR spectrum of samples from 2000 cm-1 to 4000 cm-1 . Thermal properties and temperature variation with oscillating magnetic field was investigated by RF induction method. That showed increasing temperatures with decreasing concentration of Zinc content.Also Increase in temperature was observed directly related to the frequency of applied magnetic field and concentration of Cobalt in the sample. SAR values for the sample were estimated using specific heat of samples and temperature slope and it was observed that SAR is directly related to cobalt content as well as inversely to the Zn content in the samples.

Adverse gastrointestinal events with sodium polystyrene sulphonate and calcium polystyrene sulphonate use in dialysis patients: a nationwide registry study.

Sodium polystyrene sulphonate (SPS) and calcium polystyrene sulphonate (CPS) are commonly used cation-exchange resins for the treatment and control of hyperkalaemia. However, their use (particularly SPS) has been limited by reports of adverse gastrointestinal (GI) events. The safety of these compounds in patients undergoing dialysis requires larger investigation. To study the occurrence of adverse GI events (occlusion, perforation, thrombosis/ischaemia) in the periods of SPS or CPS exposition versus the periods without exposition in dialysis patients. Dialysis patients were extracted from the French National Registry and merged with the French hospital discharge database (between 2006 and 2017). For our primary analysis, we used patients who had any claim of SPS use (n = 43 771). Time-varying Cox models, negative binomial regression and pre- versus post-treatment average treatment effects. The mean age was 66 ± 15 years, 37% were female and 92% were undergoing haemodialysis. Over a 1-year follow-up, patients on periods with SPS (on-SPS) did not present an increased risk of adverse GI events versus the periods without SPS (off-SPS): incidence rate (IR)(per 1000person years) = 7.4 (6.4-8.7) versus 9.5 (8.1-11.0); adjusted hazard ratio (HR) (95% CI) = 0.81 (0.60-1.09), P = 0.17. Patients exposed to SPS did not experience a higher rate of adverse GI events in the year after SPS initiation versus the year before SPS initiation; P-value for parallel trend = 0.87. Patients on-CPS also did not show an increased risk of adverse GI events versus off-CPS: IR (per 1000py) = 8.6 (5.1-11.9) versus 7.8 (5.1-11.9); adjusted HR (95% CI) = 0.76 (0.31-1.80), P = 0.52. The rates of adverse GI events in the periods on and off exposure were also similar over a follow-up of 5 years. Our large, nationwide study shows that the incidence of adverse GI events in patients undergoing dialysis was low and that neither the use of SPS nor CPS was associated with increased GI events risk.

Optimisation of size-exclusion chromatography with diode array detector for aquatic organic matter profiling using design of experiments: application to tropical reservoirs

ABSTRACT In this article, a size-exclusion chromatography with diode array detector (HPSEC-DAD) method was developed to determine the molecular weight distribution of natural aquatic organic matter. First, a variable screening was performed using sodium polystyrene sulphonate (PSS) standards, verifying the significant effects of ionic strength and flow rate of the mobile phase and the injection volume on resolution and final retention time. The method was then optimised using a Box – Behnken design (BBD), obtaining optimal values of 60 mM (ionic strength), 70 μL (injection volume) and 1.2 mL/min (flow rate). The process was repeated with the same design, using natural water as analyte and introducing peak area as a response, achieving optimum values of 30 mM (ionic strength), 60 μL (injection volume) and 1.17 mL/min (flow rate). In view of this discrepancy, the results of both optimal methods, using standard humic acid, were compared with the results reported in the literature, resulting in lower relative errors with the PSS method than with the natural water method. Under PSS method conditions, different samples of natural water were analysed, and it was possible to distinguish between the molecular weight profiles of organic matter coming from different environments.

Graphene coated textile based highly flexible and washable sports bra for human health monitoring

In this research work, graphene-based highly, conductive, flexible, washable, and breathable textile electrodes have been developed using the pad-dry-cure method. The results show that the electrical conductivity of the graphene-coated textile electrodes was significantly improved from 3.5 MΩ to 400 ± 5.0 kΩ for 12 padding passes. The deposition of poly(3,4-ethylenedioxythiophene) polystyrene sulphonate (PEDOT:PSS) was acquired on reduced graphene oxide (rGO) coated substrate using layer by layer (LbL) technique. The resultant electrodes showed decreased sheet resistance from 150 to 50 kΩ for PEDOT:PSS with a low impedance of 40–150 Hz over the electric potential of 1.0 mV for the detection of high-quality electrocardiograms (ECG) and pulse rate response in different conditions such as rest, walking and running. Consequently, the effect of post-treatment was also analyzed using 5.0 wt% of ethylene glycol (EG) and dimethyl sulfoxide (DMSO), respectively. The sheet resistance was further decreased from 40 kΩ to 130 ±0.5 Ω, which is appropriate for the detection of highly sensitive pulse rate response. The study demonstrates that the pad-dry-cure method can potentially be used for the development of graphene-coated wearable electronic textiles for biomedical and health monitoring devices.

Magnetic Field Implementing into the Electroluminescence of OLED Devices Doped with CoFe2O4 Nanoparticles

Cobalt ferrite magnetic nanoparticles (CoFe2O4 MNPs) were successfully prepared by citric acid-assisted sol-gel auto combustion method and used in emissive layer of organic light emitting diode (OLED). Dimensional, structural and magnetic properties of CoFe2O4 nanoparticles (NPs) were recearched and compared by using X-ray diffraction (XRD), scanning electron microscopy (SEM), and vibrating sample magnetometer (VSM). CoFe2O4 MNPs were utilized at various concentrations (0.5 wt%, 1.0 wt% and 2.0 wt%) in the emissive layer of the OLEDs. The luminance, current efficiency and the electroluminescence characteristics of the devices with and without CoFe2O4 MNPs were investigated. An external magnetic field, Bext, has also been applied to the OLEDs doped with MNPs while under operation. Effects of MNPs on OLED characteristics under Bext were studied thoroughly. In the tailored device architecture, poly (3,4-ethylenedioxythiophene): poly polystyrene sulphonate (PEDOT: PSS) and poly(2-methoxy-5-(2-ethylhexyloxy))-1,4-phenylene vinylene (MEH-PPV) were used as a hole transport layer (HTL) and an emissive layer respectively with ITO/PEDOT: PSS/ MEH-PPV: CoFe2O4/Ca/Al device architecture. The obtained results of the fabricated OLEDs were enhanced in the presence of CoFe2O4 NPs under Bext due to providing density of states in the polymer matrices. The turn-on voltage was diminished slightly in the device doped with 0.5 % wt MNP compared to the devices with other concentrations of MNPs.

Pivotal clinical trials, meta-analyses and current guidelines in the treatment of hyperkalemia.

Hyperkalemia (HK) is the most common electrolyte disturbance observed in patients with advanced stages of chronic kidney disease (CKD), is a potentially life-threatening clinical condition due to an increased risk of fatal arrhythmias, and strongly impacts the quality of life and prognosis of CKD patients. Moreover, while renin-angiotensin-aldosterone system inhibitors (RAASIs) represent the most cardio-nephro-protective drugs used in clinical practice, the treatment with these drugs per se increases serum potassium (sK) values, particularly when heart failure and diabetes mellitus coexist. In fact, the onset or recurrence of HK is frequently associated with not starting, down-titrating or withdrawing RAASIs, and is an indication to begin renal replacement treatment in end-stage renal disease. Current strategies aimed at preventing and treating chronic HK are still unsatisfactory, as evidenced by the relatively high prevalence of HK also in patients under stable nephrology care, and even in the ideal setting of randomized clinical trials. Indeed, dietary potassium restriction, the use of sodium bicarbonate or diuretics, the withdrawal or down-titration of RAASIs, or the administration of old potassium binders, namely sodium polystyrene sulphonate and calcium polystyrene sulphonate, have limited efficacy and are poorly tolerated; therefore, these strategies are not suitable for long-term control of sK. As such, there is an important unmet need for novel therapeutic options for the chronic management of patients at risk for HK. The development of new potassium binders may change the treatment landscape in the near future. This review summarizes the current evidence on the treatment of chronic HK in cardio-renal patients.

Aqueous phase and amorphous state room temperature phosphorescence from a small aromatic carbonyl derivative

Harvesting triplet excitons via room temperature phosphorescence (RTP) in solution or amorphous state from purely organic chromophores is a formidable challenge. Supramolecular hybrid co-assembly between a brominated aromatic carbonyl derivative (BrPhS) and laponite clay (LP) particles is shown to result in remarkable triplet stabilization to result room temperature phosphorescence (RTP) in aqueous solution as well as in amorphous thin films. This remarkable feature is realized by means of highly organized, rigid molecular network of the dye molecules on the inorganic scaffold which reduces the vibrational dissipations as well as limits the oxygen diffusion to facilitate the triplet harvesting under ambient conditions. The water soluble phosphor, BrPhS is also shown to be an excellent triplet emitter in other amorphous polymer matrices like polyvinyl alcohol (PVA) and sodium polystyrene sulphonate (PSS) with phosphorescence quantum yield over 30% in air.

Could drug burden be associated with severe periodontitis in patients receiving haemodialysis?

Periodontitis increases the risk of cardiovascular disease in the general population by triggering systemic inflammation. To investigate the relationship between systemic inflammation and periodontitis, and clarify any association between severe periodontitis and the medications used by patients receiving haemodialysis. A cross-sectional study. The study was undertaken with 56 patients receiving haemodialysis. Demographic and laboratory data and prescribed drugs regularly used by patients were recorded from hospital records. During the dialysis session, a validated Xerostomia Inventory score was completed. A complete dental/periodontal examination was also undertaken on all patients by the same periodontist. In the study population, stage I periodontitis was determined in 41%, stage II periodontitis in 17%, stage III periodontitis in 21%, and stage IV periodontitis in 21%. Male gender, hypertension, coronary artery disease, β antagonists, calcium channel blockers, sodium polystyrene sulphonate, teeth brushing less than twice a day and high sensitive C-reactive protein > 8 mg/l were significantly associated with severe periodontitis. Drugs, including β antagonists, calcium channel blockers, polystyrene sulphonate, co-morbid conditions and poor or insufficient oral care could facilitate an increase in the severity of periodontitis in patients receiving haemodialysis. Severe periodontitis also seems to be associated with cardiovascular disease and inflammation in patients with chronic renal disease.

Initiation of sodium polystyrene sulphonate and the risk of gastrointestinal adverse events in advanced chronic kidney disease: a nationwide study.

BackgroundDespite long-standing clinical use of sodium polystyrene sulphonate (SPS) for hyperkalaemia management in chronic kidney disease (CKD), its safety profile remains poorly investigated.MethodsWe undertook an observational analysis of nephrology-referred adults with incident CKD Stage 4+ in Sweden during 2006–16 and with no previous SPS use. We studied patterns of use and adverse events associated to SPS initiation during follow-up. Patterns of SPS use were defined by chronicity of treatment and by prescribed dose. We estimated hazard ratios (HRs) and 95% confidence intervals (CIs) associated with SPS initiation (time-varying exposure) for the risk of severe (intestinal ischaemia, thrombosis or ulceration/perforation) and minor (de novo dispensation of laxatives or anti-diarrheal drugs) gastrointestinal (GI) events.ResultsOf 19 530 SPS-naïve patients with CKD, 3690 initiated SPS during follow-up. A total of 59% took SPS chronically, with an average of three dispensations/year. The majority (85%) were prescribed lower dosages than specified on the product label. During follow-up, 202 severe and 1149 minor GI events were recorded. SPS initiation was associated with a higher incidence of severe adverse events [adjusted HR 1.25 95% CI 1.05–1.49)], particularly in those receiving per label doses [1.54 (1.09–2.17)] and mainly attributed to ulcers and perforations. SPS initiation was also associated with higher incidence of minor GI events [adjusted HR 1.11 (95% CI 1.03–1.19)], regardless of dose, and mainly accounted for by de novo dispensation of laxatives.ConclusionsInitiation of SPS in patients with advanced CKD is associated with a higher risk of severe GI complications as well as the initiation of GI-related medications, particularly when prescribed at per label doses.

Laser Patterned Polymer/Carbon Nanotubes Composite Electrodes for Flexible Silicon Nanowire Transistors.

Fabrication techniques such as laser patterning offer excellent potential for low cost and large area device fabrication. Conductive polymers can be used to replace expensive metallic inks such as silver and gold nanoparticles for printing technology. Electrical conductivity of the polymers can be improved by blending with carbon nanotubes. In this work, formulations of acid functionalized multiwalled carbon nanotubes (f-MWCNTs) and poly(ethylenedioxythiophene) [PEDOT]:polystyrene sulphonate [PSS] were processed, and thin films were prepared on plastic substrates. Conductivity of PEDOT:PSS increased almost four orders of magnitude after adding f-MWCNTs. Work function of PEDOT:PSS/f-MWCNTs films was ∼0.5 eV higher as compared to the work function of pure PEDOT:PSS films, determined by Kelvin probe method. Field-effect transistors source-drain electrodes were prepared on PET plastic substrates where PEDOT:PSS/f-MWCNTs were patterned using laser ablation at 44 mJ/pulse energy to define 36 μm electrode separation. Silicon nanowires were deposited using dielectrophoresis alignment technique to bridge laser patterned electrodes. Top-gated nanowire field effect transistors were completed by depositing parylene C as polymer gate dielectric and gold as the top-gate electrode. Transistor characteristics showed p-type conduction with excellent gate electrode coupling, with an ON/OFF ratio of ∼200. Thereby, we demonstrate the feasibility of using high workfunction, printable PEDOT:PSS/f-MWCNTs composite inks for laser patterned source/drain electrodes for nanowire transistors on flexible substrates.

Sodium polystyrene sulphonate: risk of severe GI events

Sodium polystyrene sulphonate: risk of severe GI events

Effect of negative functionalisation of gold nanorods on conformation and activity of human serum albumin

The theranostic applications of gold nanorods (AuNRs) are limited due to the presence of cytotoxic cetrimonium bromide (CTAB) stabiliser, leading to the instigation of alternate stabilisers like negatively charged polystyrene sulphonate (PSS). Despite previous reports suggesting the impact of PSS-AuNRs on cells, their effect on the most abundant protein in plasma, i.e. human serum albumin (HSA), has not been studied before. Hence, the impact of PSS-AuNRs on HSA was thoroughly examined using varied spectroscopic techniques. The absorbance and fluorescence spectroscopic findings suggested the extent of ground-state complexation and tryptophan domain disruptions of HSA for different AuNR concentrations, which were also suggested based on size measurements and activation energy calculations for complex formation. Modifications in the hydrophobic environment of HSA were evaluated using synchronous fluorescence, whereas the secondary structural damages were explained using circular dichroism (CD) and FTIR analyses. Additional studies to analyse protein denaturation, fibrillation, esterase activity, and free thiol were carried out to understand structural and functional changes. The study suggested that PSS-AuNRs showed concentration-dependent alterations in HSA structure, but the extent of protein toxicity was considerably lesser for PSS-AuNRs of similar dimensions compared to the data available for CTAB-AuNRs; thus, highlighting that PSS-AuNRs could be safer for biomedical applications.

The influence of macropores on PEDOT/PSS microelectrode coatings for neuronal recording and stimulation

Recent trends towards smaller electrodes for improved spatial resolution have seen the rise of rough electrode coatings, such as conducting polymer (CPs), to increase electrochemical surface area and subsequently recording and stimulation performance. Here, we directly compare the influence of macropores in poly(3,4-ethylenedioxythiophene)/polystyrene sulphonate (PEDOT/PSS) coatings hypothesised to further increase electrochemical surface area and gain new insights into the influence of surface morphology on CP signal transduction. Macroporous PEDOT/PSS polymerised at the highest charge density of 637 mC cm−2 displayed significant reductions in impedance magnitude (at 100 Hz) and thermal noise and significant increases in the charge injection limit when compared to untemplated PEDOT/PSS. Macroporous PEDOT/PSS was more susceptible to delamination following long-term biphasic stimulation, however, it displayed an interesting improvement in impedance throughout the experiment. Biocompatibility of both untemplated and macroporous PEDOT/PSS coatings alongside primary hippocampal neurons in-vitro was demonstrated via neuronal viability assays. Improvements were noted in electrochemical properties achieved by the macroporous coatings, meanwhile in-vitro recording and stimulation performance favoured untemplated PEDOT/PSS as measured through signal-to-noise ratios and direct neuronal responses to biphasic stimuli, respectively. Whilst the macroporous structures perform similarly to untemplated PEDOT/PSS in-vitro, the significant improvement in their electrochemical surface area at high deposition charge densities may offer them use in fields of drug delivery and biosensing.

Electrochemical and photoelectrochemical properties of the interface between titania nanotubes covered by conducting polymer in aqueous by conducting polymer in aqueous electrolytes – The effect of various geometry and electrolytes concentration

In the present work we show the impact of nanotubes (NTs) geometry of titania utilized as a substrate in organic-inorganic systems acting as a p-n junction on efficient conversion of radiation energy into electrochemical energy. The electrolytic bath composition and electrolysis conditions were controlled in order to obtain TiO2NTs of various geometry as a result of electrochemical oxidation of titanium foil. The electrode material was characterized using scanning electron microscopy, Raman and UV–vis spectroscopies in order to investigate their morphology, crystallinity and absorbance ability, respectively. According to SEM inspection, the electrolyte bath composition (water content) and duration of electrolysis significantly affects TiO2NTs morphology, namely the internal diameter and the layer thickness. The TiO2NTs electrode/electrolyte interface characterized using electrochemical impedance spectroscopy (EIS) exhibits varied impedance parameters depending on the outer K2SO4 electrolyte concentration (in the range of: 0.01–0.2 M) as the electric charge distribution at the interface is concentration dependent. The series of hydrogenated titania substrates were electrochemically modified by the conducting polymer: poly(3,4-ethylenedioxytiophene) doped with polystyrene sulphonate (pEDOT:PSS) thin film. The optimal geometry of titania was determined based on the photocurrent density recorded for the composite material (TiO2NTs/pEDOT:PSS). The most photoactive organic inorganic junction is composed of titania tubes of 2.5 µm length, the outer diameter equal to 205 nm giving the real surface area equal to 49.9 cm2 per 1 cm2.

Evidence in support of hyperkalaemia management strategies: A systematic literature review.

Hyperkalaemia is a potentially life-threatening condition that can be managed with pharmacological and non-pharmacological approaches. With the recent development of new hyperkalaemia treatments, new information on safe and effective management of hyperkalaemia has emerged. This systematic literature review (SLR) aimed to identify all relevant comparative and non-comparative clinical data on management of hyperkalaemia in adults. Our secondary aim was to assess the feasibility of quantitatively comparing randomised controlled trial (RCT) data on the novel treatment sodium zirconium cyclosilicate (ZS) and established pharmacological treatments for the non-emergency management of hyperkalaemia, such as the cation-exchangers sodium/calcium polystyrene sulphonate (SPS/CPS). MEDLINE, Embase and the Cochrane Library were searched on 3rd April 2017, with additional hand-searches of key congresses and previous SLRs. Articles were screened by two independent reviewers. Eligible records reported interventional or observational studies of pharmacological or non-pharmacological management of hyperkalaemia in adults. Database searches identified 2,073 unique records. Two hundred and one publications were included, reporting 30 RCTs, 29 interventional non-RCTs and 43 observational studies. Interventions investigated in RCTs included ZS (3), SPS/CPS (3), patiromer (4) and combinations of temporising agents (6 RCTs). A robust and meaningful indirect treatment comparison between ZS and long-established cation-binding agents (SPS/CPS) was infeasible because of heterogeneity between studies (including time points and dosing) and small sample size in SPS/CPS studies. Despite hyperkalaemia being associated with several chronic diseases, there is a paucity of high-quality randomised evidence on long-established treatment options (SPS and CPS) and a limited evidence base for hyperkalaemia management with these agents.

Multi-functional wool fabrics by graft-copolymerisation with polystyrene sulphonate: their enhanced fire retardancy, mechanical properties, and stain-resistance

pSS-Grafted wool fabrics showed enhanced fire retardancy, tensile strength and stain-resistance against an acid dye-based stain.

Carbon Nano-Onions as a Functional Dopant to Modify Hole Transporting Layers for Improving Stability and Performance of Planar Perovskite Solar Cells

Poly (3,4-ethylenedioxythiophene) polystyrene sulphonate (PEDOT:PSS) is the most widely used hole transporting layer (HTL) in planar perovskite solar cells, which shows excellent optical, electrical properties and good compatibility with low temperature, solution and flexible processing. Nevertheless, the acidic and hygroscopic property of PEDOT:PSS restricts its film conductivity and leads to the degradation of device stability. Herein, for the first time, we introduce the unprecedentedly zero-dimensional dopant of carbon nano-onions (CNOs) and the functionalized oxidized carbon nano-onions (ox-CNOs) to modify the PEDOT:PSS HTL. Besides the merits of high conductivity and suitable energy level, the CNOs and ox-CNOs modified PEDOT:PSS HTLs could provide a superior perovskite crystalline film with large-scale grains and orderly grain boundaries exhibiting a high surface tension with the hydrophobic property, resulting in a significant enhancement of PCE from 11.07% to 15.26%. Moreover, by suppressing the corrosion effect of PEDOT:PSS on ITO electrode, a dramatic improvement in the device stability has also been obtained.

The influence of distribution and deposit of conductive coating on shielding effectiveness of textiles

This study presents the investigation of electrically conductive fabrics with low resistivity, coated with formulation containing the conjugated polymer system – poly(3,4-ethylenedioxythiophene)-polystyrene sulphonate (PEDOT-PSS). The samples of fabrics were coated with PEDOT-PSS, using a screen printing method, by different patterns or coating their surface fully with different coating deposit. Methods for measurement of electrostatic properties, reflection and transmission as well as the assessment of electromagnetic radiation (EMR) shielding effectiveness were used for the characterization of electrical properties of developed samples. EMR shielding properties were investigated within 2–12 GHz frequency bands. The highest attenuation of the electromagnetic energy among tested fabrics was obtained on the fabrics fully coated with paste and it depended on deposit considerably. The influence of distribution and deposit of conductive coating on shielding effectiveness of textiles were determined. Correlation between shielding effectiveness and electrostatic properties of developed coated fabrics was also discussed. Electrical properties of samples coated with formulation containing PEDOT-PSS were compared with these of fabrics with metalized yarns, developed by us earlier. The results of EMR shielding measurements showed that fabrics coated with the paste containing conductive polymer system compared to fabrics with in-weaved conductive metalized yarns have certain advantages as EMR shields.

Silicon-Quantum-Dot Light-Emitting Diodes With Interlayer-Enhanced Hole Transport

Despite the technological importance of silicon quantum dots (Si QDs) which are solely made of abundant and nontoxic Si, Si-QD light-emitting diodes (LEDs) clearly lag behind those based on other QDs, especially Cd- or Pb-containing QDs. It is imperative that novel measures should be taken to boost the performance of Si-QD LEDs. Here, we demonstrate that Si-QD LEDs can work much more efficiently after the use of interlayers between indium tin oxide (ITO) and poly(ethylene-dioxythiophene):polystyrene sulphonate (PEDOT:PSS) to enhance the hole transport of the devices. The interlayer of dipyrazino (2, 3-f:2 ′, 3 ′-h) quinoxaline-2,3,6,7,10,11-hexacarbonitrile (HAT-CN) or MoO3 increases the work function of ITO and improves the band alignment, leading to better hole injection from ITO to PEDOT:PSS. The resulting mitigated charge unbalance causes both the external quantum efficiency (EQE) and stability of Si-QD LEDs to significantly increase (up to ∼170% for EQE and ∼240% for device half-lifetime). The highest EQE of ∼2.4% obtained in the current work is among the best values that have been reported for Si-QD LEDs. Even without encapsulation, the device half-lifetime is up to ∼8.5 h. The enhancement of the hole transport induced by MoO3 is more significant than that induced by HAT-CN. Therefore, MoO3 more significantly enhances the performance of Si-QD LEDs than HAT-CN.

Effect of the polyelectrolyte coating on the photothermal efficiency of gold nanorods and the photothermal induced cancer cell damage.

Coating gold nanorods (GNRs) with polyelectrolytes is an effective approach to make them biocompatible for potential use in photothermal treatment (PTT) of cancer. The authors report the effect of coating of the GNRs with polystyrene sulphonate (PSS-GNRs) and PSS plus poly di-allyl di-methyl ammonium chloride (PDDAC-GNRs) on its photothermal conversion efficiency (PTE), cellular uptake and subsequently the photothermal induced cytotoxicity in human oral cancer cells (NT8e). Coating of GNRs with PSS led to decrease in PTE by ∼30% and further coating it with PDDAC led to its increase to similar level, with respect to as- prepared GNRs. The cellular uptake of PDDAC-GNRs in cancer cells was double than that for PSS-GNRs. PTT of cancer cells after treatment with 60 pM of either PDDAC-GNRs or PSS-GNRs resulted in cytotoxicty of ∼90%. At higher concentration of 120 pM, while PSS-GNRs showed no further change, for PDDAC-GNR the photothermal induced cytotoxicity decreased to ∼50%. The broadening of longitudinal surface plasmon peak of PDDAC-GNRs and appearance of dark clusters in cells under bright-field microscope suggested intracellular clustering of PDDAC-GNRs. In conclusion, despite high PTE and cellular uptake of PDDAC-GNRs, its intracellular clustering (due to acidic pH ) adversely affect the PTT of cancer cells.