Trinuclear ruthenium(II) polypyridyl complexes: Evaluation as photosensitizers for enhanced cervical cancer treatment.

Trinuclear ruthenium(II) polypyridyl complexes anchored to benzimidazole-triazine / trisamine scaffolds were investigated as photosensitizers for photodynamic therapy. The trinuclear complexes were noted to produce a significant amount of singlet oxygen in both DMF and aqueous media, are photostable and show appreciable emission quantum yields (ɸem). In our experimental setting, despite the moderate phototoxic activity in the HeLa cervical cancer cell line, the phototoxic indices (PI) of the trinuclear complexes are superior relative to the PIs of a clinically approved photosensitizer, Photofrin®, and the pro-drug 5-aminolevulinic acid (PI: >7 relative to PI: >1 and PI: 4.4 for 5-aminolevulinic acid and Photofrin®, respectively). Furthermore, the ruthenium complexes were noted to show appreciable long-term cytotoxicity upon light irradiation in HeLa cells in a concentration-dependent manner. Consequently, this long-term activity of the ruthenium(II) polypyridyl complexes embodies their ability to reduce the probability of the recurrence of cervical cancer. Taken together, this presents a strong motivation for the development of polymetallic complexes as anticancer agents.

Blue-Light-Activated Water-Soluble Sn(IV)-Porphyrins for Antibacterial Photodynamic Therapy (aPDT) against Drug-Resistant Bacterial Pathogens.

Antimicrobial resistance has emerged as a global threat to the treatment of infectious diseases. Antibacterial photodynamic therapy (aPDT) is a promising alternative approach and is highly suitable for the treatment of cutaneous bacterial infections through topical applications. aPDT relies on light-responsive compounds called photosensitizer (PS) dyes, which generate reactive oxygen species (ROS) when induced by light, thereby killing bacterial cells. Despite several previous studies in this area, the molecular details of targeting and cell death mediated by PS dyes are poorly understood. In this study, we further investigate the antibacterial properties of two water-soluble Sn(IV) tetrapyridylporphyrins that were quaternized with methyl and hexyl groups (1 and 2). In this follow-up study, we demonstrate that Sn(IV)-porphyrins can be photoexcited by blue light (a 427 nm LED) and exhibit various levels of bactericidal activity against both Gram-(+) and Gram-(-) strains of bacteria. Using localization studies through fluorescence microscopy, we show that 2 targets the bacterial membrane more effectively than 1 and exhibits comparatively higher aPDT activity. Using multiple fluorescence reporters, we demonstrate that photoactivation of 1 and 2 results in extensive collateral damage to the bacterial cells including DNA cleavage, membrane damage, and delocalization of central systems necessary for bacterial growth and division. In summary, this investigation provides deep insights into the mechanism of bacterial killing mediated by the Sn(IV)-porphyrins. Moreover, our approach offers a new method for evaluating the activity of PS, which may inspire the discovery of new PS with enhanced aPDT activity.

Photodynamic antimicrobial chemotherapy activities of phthalocyanine-antibiotic conjugates against bacterial biofilms and interactions with extracellular polymeric substances.

This study sheds light on how to rationally design efficient photodynamic antimicrobial chemotherapy (PACT) agents by covalently linking phthalocyanines (Pcs) as photosensitizers with an antibiotic: Ciprofloxacin (CIP). Pcs used are zinc (II) 3-(4-((3,17,23-tris(4-(Benzo(d)thiazol-2-yl] thiol) phthalocyanine-9-yl) oxy) phenyl) propanoic acid (1) and zinc (II) 3-(4-(3,17,23-tris(3-(4-(triphenylphosphine) butyl) benzo[d]thiazol-3-ium bromide phthalocyanine-9-yl) oxy) phenyl) propanoic acid (2). High singlet oxygen quantum yields are observed in the presence of CIP. Square wave voltammetry was used to analyse the Pc-CIP uptake by bacteria biofilms of Streptococcus pneumoniae (S. pneumonia) and Escherichia coli (E. coli). Electrochemical impedance spectroscopy and scanning electron spectroscopy were used to study the stability of the biofilms in the presence Pc-CIP complexes and when exposed to light. Raman and time of flight-secondary ion mass spectrometry (TOF-SIMS) are used to identify the breakdown of cellular components of the biofilm and penetration of the Pc-CIP into the biofilms, respectively.

The photodynamic activity properties of a series of structurally analogous tetraarylporphyrin, chlorin and N-confused porphyrin dyes and their Sn(IV) complexes.

A series of tetraarylporphyrin, -chlorin and N-confused porphyrin dyes with 4­methoxy­meso-aryl rings (1-Por, 1-Chl and 1-NCP) and their Sn(IV) complexes (1-SnPor, 1-SnChl and 1-SnNCP) have been synthesized and characterized. The heavy atom effect of the Sn(IV) ion results in relatively high singlet oxygen quantum yield values of 0.67, 0.71 and 0.85 for 1-SnPor, 1-SnChl and 1-SnNCP, respectively. The photodynamic activities of 1-Por, 1-Chl, 1-NCP, 1-SnPor, 1-SnChl and 1-SnNCP were determined against MCF-7 breast cancer cells through illumination with Thorlabs 625 or 660 nm (240 or 280 mW.cm-2) light emitting diodes (LEDs) for 20 min. The IC50 values for 1-SnChl and 1-SnNCP lie between 1.4 - 6.1 and 1.6 - 4.8 µM upon photoirradiation with the 660 and 625 nm LEDs, respectively, while higher values of >10 µM were obtained for 1-SnPor and the free base dyes. In a similar manner, 1-SnChl and 1-SnNCP were found to also have significantly higher photodynamic antimicrobial activity against planktonic Gram-(+) Staphylococcus aureus and Gram-(-) Escherichia coli bacteria than the other dyes studied. Upon illumination with Thorlabs 625 and 660 nm LEDs for 75 min, Log10 reduction values of 7.62 and > 2.40-3.69 were obtained with 1 and 5 µM solutions, respectively.

The development of folate-functionalised palladium nanoparticles for folate receptor targeting in breast cancer cells.

Folate receptor-targeted therapy has excellent prospects for the treatment of breast cancer. A non-toxic concentration of folate-conjugated palladium-based nanoparticles was used to target the overexpressed folate receptor on breast cancer cells. The folate-conjugated nanoparticles were tailored to accumulate selectively in cancer cells relative to normal cells via the folate receptor. The MDA-MB-231, MDA-MB-468, MCF-7 breast cancer cell lines, and MCF-10A normal cell lines were used in the study. Qualitative and quantitative analysis of nanoparticle cellular uptake and accumulation was conducted using transmission electron microscopy and inductively coupled plasma-optical emission spectroscopy. The findings proved that folate-conjugated palladium nanoparticles successfully and preferentially accumulated in breast cancer cells. We conclude that folate-conjugated palladium nanoparticles can be potentially used to target breast cancer cells for radiopharmaceutical applications.

Single vs sandwich aptamers: Towards the detection of human epidermal growth factor receptor 2 using composites of phthalocyanine and nanoparticles.

The superiority of the sandwich over a single aptamer based aptasensor assay for the detection of the human epidermal growth factor receptor 2 (HER2) is demonstrated for the first time. Cobalt tris-3,5 dimethoxy-phenoxy pyridine (5) oxy (2)- carboxylic acid phthalocyanine (CoMPhPyCPc) and sulphur/nitrogen doped graphene quantum dots (SNGQDs) and cerium oxide nanoparticles (CeO2NPs) nanocomposite (SNGQDs@CeO2NPs) were used for electrode modification of glassy carbon electrode (GCE) both individually and combined to form the substrates: GCE/SNGQDs@CeO2NPs, GCE/CoMPhPyCPc and GCE/SNGQDs@CeO2NPs/CoMPhPyCPc. The designed substrates were used as immobilization platforms for the amino functionalized HB5 aptamer for the development of both single and sandwich aptasensor assays. A novel bioconjugate, made of the HB5 aptamer and nanocomposite (HB5-SNGQDs@CeO2NPs) was fabricated, and characterized using ultra-violet/visible, Fourier transform infrared, and Raman spectroscopies as well as scanning electron microscopy. HB5-SNGQDs@CeO2NPs was applied as a secondary aptamer in the design of novel sandwich assays towards the electrochemical detection of HER2. The performance of the designed aptasensors were evaluated using electrochemical impedance spectroscopy. The sandwich assay gave low limit of detection of 0.00088 pg/mL, high sensitivity of 773925 Ω pg-1mL, showed stability, and good precision in real samples towards HER2 detection.

The Photodynamic Anticancer and Antibacterial Activity Properties of a Series of meso-Tetraarylchlorin Dyes and Their Sn(IV) Complexes.

A series of tetraarylchlorins with 3-methoxy-, 4-hydroxy- and 3-methoxy-4-hydroxyphenyl meso-aryl rings (1-3-Chl) and their Sn(IV) complexes (1-3-SnChl) were synthesized and characterized so that their potential utility as photosensitizer dyes for use in photodynamic therapy (PDT) and photodynamic antimicrobial chemotherapy (PACT) can be assessed. The photophysicochemical properties of the dyes were assessed prior to in vitro PDT activity studies against MCF-7 breast cancer cells through irradiation with Thorlabs 625 or 660 nm LED for 20 min (240 or 280 mW·cm-2). PACT activity studies were performed against both planktonic bacteria and biofilms of Gram-(+) S. aureus and Gram-(-) E. coli upon irradiation with Thorlabs 625 and 660 nm LEDs for 75 min. The heavy atom effect of the Sn(IV) ion results in relatively high singlet oxygen quantum yield values of 0.69-0.71 for 1-3-SnChl. Relatively low IC50 values between 1.1-4.1 and 3.8-9.4 µM were obtained for the 1-3-SnChl series with the Thorlabs 660 and 625 nm LEDs, respectively, during the PDT activity studies. 1-3-SnChl were also found to exhibit significant PACT activity against planktonic S. aureus and E. coli with Log10 reduction values of 7.65 and >3.0, respectively. The results demonstrate that the Sn(IV) complexes of tetraarylchlorins merit further in depth study as photosensitizers in biomedical applications.

Sn(IV)-porphyrinoids for photodynamic anticancer and antimicrobial chemotherapy.

Photodynamic therapy (PDT) is a mode of treatment for different types of cancers, which involves a nontoxic photosensitizer (PS), a light source to activate the PS, and ground-state molecular oxygen (3O2). Light activation of the PS leads to the generation of reactive oxygen species (ROS), which initiates a toxic effect on the surrounding cellular substrates, thereby destroying the cancerous cells. The commercially used PDT drug Photofrin® which is a tetrapyrrolic porphyrin-based photosensitizer has drawbacks such as aggregation in water, prolonged skin photosensitivity, variability in chemical compositions, and minimal absorbance in the red-light region. Metallation of the porphyrin core with diamagnetic metal ions aids the photogeneration of singlet oxygen (ROS). Metalating with Sn(IV) provides a six-coordination octahedral geometry with trans-diaxial ligands. This approach suppresses aggregation in aqueous media and increases ROS generation upon light exposure due to the heavy atom effect. Bulky trans-diaxial ligation hinders the approach of the Sn(IV) porphyrins, thereby suppressing aggregation effects. In this review, we document the recently reported Sn(IV) porphyrinoids and their photodynamic therapy (PDT) and photodynamic antimicrobial chemotherapy (PACT) activity properties. In a similar manner to PDT, the photosensitizer is used to kill the bacteria upon irradiation with light during PACT. Often, bacteria develop resistance against conventional chemotherapeutic drugs over time, decreasing their antibacterial properties. However, in the case of PACT, it is difficult to generate resistance against singlet oxygen produced by the photosensitizer.

The in-vitro proliferation-suppression of MCF-7 and HeLa cell lines mediated by differently substituted ionic phthalocyanines in sonodynamic therapy supplemented-photodynamic therapy.

This work focuses on the study of the effects of the ultrasonic frequency (MHz) and power (W.cm-2) on the stability, reactive oxygen species yields and cytotoxicity activities of differently substituted ionic phthalocyanines (Pcs) in sonodynamic therapy (SDT). Four ultrasonic parameters were investigated: Par I (1 MHz: 1 W.cm-2), Par II (1 MHz: 2 W.cm-2), Par III (3 MHz: 1 W.cm-2) and Par IV (3 MHz: 2 W.cm-2). A higher degradation of the Pcs was observed with increasing power at the Par II. Two reactive oxygen species (ROS) were detected in the ultrasound treated Pcs: singlet oxygen and hydroxyl radicals. Due to minimal degradation of most Pcs, Par I was chosen for SDT, photodynamic therapy (PDT), and photo-sonodynamic therapy (PSDT) against Michigan Cancer Foundation-7 and Henrietta Lacks cancer cell lines. PSDT generally showed improved therapeutic efficacies of the Pcs compared to the SDT and PDT mono treatments.

A hypoxia responsive silicon phthalocyanine containing naphthquinone axial ligands for photodynamic therapy activity.

A liposome loaded­silicon (IV) phthalocyanine (SiPc) containing naphthoquinone axial ligands as hypoxia-responsive a prodrug-like moieties (Prodrug-SiPc), is herein reported. With the help of computational methods, this study assessed the photophysical, photochemical and electrochemical redox properties of the Prodrug-SiPc to elucidate the relationship between material structure and properties. The attachment of the axial quinoid moieties endowed the Prodrug-SiPc with Type I/II photochemical and prodrug-like properties. Following liposomal encapsulation, the therapeutic efficacy of Prodrug-SiPc-liposomes was investigated against Michigan Cancer Foundation-7 (MCF-7) and Henrietta Lacks (Hela) cancer cells as in vitro cancer models and revealed that the as-synthesized Prodrug-SiPc-liposomes are potential photodynamic therapy (PDT) drug candidates. The Prodrug-SiPc-liposome takes full advantage of the hypoxic microenvironment of tumors - a side effect PDT - to trigger therapy, resulting in significantly enhanced efficacy compared to typical PDT. This work highlights the importance of multiple characteristics in designing new and effective photosensitizer candidates.

Co phthalocyanine mediated electrochemical detection of the HER2 in the presence of Au and CeO2 nanoparticles and graphene quantum dots.

In this work, cobalt tetra phenoxy acetic acid phthalocyanine (CoTAPc) is investigated as an electron mediator, immobilization platform for an HB5 aptamer and to enhance the electrochemical signal for the detection of human epidermal growth factor receptor 2 (HER2). Furthermore, the CoTAPc was combined individually with sulphur/nitrogen doped graphene quantum dots (SNGQDs), gold nanoparticles (AuNPs) and cerium oxide nanoparticles (CeO2NPs), on a glassy carbon electrode (GCE) via sequential adsorption. The CoTAPc and SNGQDs were also π-π stacked, used for electrode modification similarly to the rest of the other surfaces and applied towards the electrochemical detection of HER2. The designed sensors were characterized using electrochemical impedance spectroscopy (EIS). The designed aptasensors showed detection limits as low as 6.0 pg/mL. The real life applicability of the designed aptasensors was tested in human serum samples. The aptasensors showed great storage stability, sensitivity and specificity towards HER2, implying great potential for applications in early diagnosis of breast cancer.

Enhanced mitochondria destruction on MCF-7 and HeLa cell lines in vitro using triphenyl-phosphonium-labelled phthalocyanines in ultrasound-assisted photodynamic therapy activity.

This work reports on the reactive oxygen species (ROS) generation and the therapeutic activities of new triphenyl-phosphonium-labelled phthalocyanines (Pcs), the 2,9,16,23-tetrakis(N-(N-butyl-4-triphenyl-phosphonium)- pyridine-4-yloxy) Zn(II) Pc (3) and 2,9,16,23-tetrakis-(N-(N-butyl-4-triphenyl-phosphonium)-morpholino) Zn(II) Pc (4) upon exposure to light, ultrasound and the combination of light and ultrasound. Two types of ROS were detected: the singlet oxygen (1O2) and hydroxyl radicals. For light irradiations, only the 1O2 was detected. An increase in the ROS generation was observed for samples treated with the combination of light and ultrasound compared to the light and ultrasound mono-treatments. The in vitro anticancer activity through photodynamic (PDT) and sonodynamic (SDT) therapy for the Pcs were also determined and compared to the photo-sonodynamic combination therapy (PSDT). The two cancer cell lines used for the in vitro studies included the Michigan Cancer Foundation-7 (MCF-7) breast cancer and Henrietta Lacks (HeLa) cervical cancer cell lines. The SDT treatments showed improved therapeutic efficacy on the cancer cells for both the Pcs compared to PDT. PSDT showed better therapeutic efficacy compared to both the PDT and SDT mono-treatments.

Reaction of Perrhenate with Phthalocyanine Derivatives in the Presence of Reducing Agents and Rhenium Oxide Nanoparticles in Biomedical Applications.

A novel alternative route to access rhenium(V)-phthalocyanine complexes through direct metalation of metal-free phthalocyanines (H2 Pcs) with a rhenium(VII) salt in the presence of various two-electron reducing agents is presented. Direct ion metalation of tetraamino- or tetranitrophthalocyanine with perrhenate (ReO4- ) in the presence of triphenylphosphine led to oxidative decomposition of the H2 Pcs, giving their respective phthalonitriles. Conversely, treatment of H2 Pcs with ReO4- employing sodium metabisulfite yielded the desired ReV O-Pc complex. Finally, reaction of H2 Pcs with ReO4- and NaBH4 as reducing agent led to the formation of rhenium oxide (Rex Oy ) nanoparticles (NPs). The NP synthesis was optimised, and the Rex Oy NPs were capped with folic acid (FA) conjugated with tetraaminophthalocyanine (TAPc) to enhance their cancer cell targeting ability. The cytotoxicity profile of the resultant Rex Oy -TAPc-FA NPs was assessed and found to be greater than 80 % viability in four cell lines, namely, MDA-MB-231, HCC7, HCC1806 and HEK293T. Non-cytotoxic concentrations were determined and employed in cancer cell localization studies. The particle size effect on localization of NPs was also investigated using confocal fluorescence and transmission electron microscopy. The smaller NPs (≈10 nm) were found to exhibit stronger fluorescence properties than the ≈50 nm NPs and exhibited better cell localization ability than the ≈50 nm NPs.

GaIIItriarylcorroles with push-pull substitutions: synthesis, electronic structure and biomedical applications.

Two A2B type H3corroles and two GaIIItriarylcorroles with carbazole substitutions at 10-positions were synthesized and characterized. An analysis of structure-property relationships of the corroles has been carried out by investigating the optical spectroscopy of the dyes to trends predicted in DFT and TD-DFT calculations. Interestingly, the photodynamic therapy (PDT) and photodynamic antimicrobial chemotherapy (PACT) activity properties of the GaIIItriarylcorroles were determined against the MCF-7 breast cancer line, and Staphyloccocus aureus (S. aureus) and Escherichia coli (E. coli), respectively. The cationic G-2Q species exhibited the most favorable properties with an IC50 value of 7.8 µM against MCF-7 cells, and Log reduction values of 7.78 and 3.26 against planktonic S. aureus and E. coli at 0.5 and 10 µM, respectively.

Design and fabrication of electrochemical sensor based on molecularly imprinted polymer loaded onto silver nanoparticles for the detection of 17-ß-estradiol.

In this research report, we prepared an electrochemical sensor based on the molecularly imprinted poly(p-aminophenol) supported by silver nanoparticles capped with 2-mercaptobenzoxazole for the selective and sensitive detection of endocrine disrupting 17-ß-estradiol (E2). The electropolymerization of the functional monomer prepared the proposed molecularly imprinted polymer (MIP) composite-based sensor in the presence of E2 as a template. The recognition materials were characterized using Fourier transform infrared, cyclic voltammetry (CV), square wave voltammetry (SWV), scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray powder diffraction techniques. The electrochemical measurements were performed by employing both CV and SWV methods. We did the optimization of critical parameters affecting the sensor performances through the experimental design and verification. The developed sensor showed a linear range from 10 pM to 100 nM with the calculated quantification and detection limits of 1.86 and 6.19 pM, respectively. The incorporation of AgNP with high electrical conductivity into the MIP matrix enhanced the sensor's performance. Furthermore, the sensor was applied to determine E2 in real water samples without any sample preconcentration steps to achieve the percent recovery of 91.87% to 98.36% and acceptable reusability and storage stability performances.

The effect of charge on Zn tetra morpholine porphyrin conjugated to folic acid-nitrogen doped graphene quantum dots for photodynamic therapy studies.

Zinc tetra morpholine porphyrin (complex 2), and its quaternized derivative (complex 3) were synthesized and conjugated to folic acid decorated nitrogen doped graphene quantum dots (FA-NGQDs) through π-π stacking to study their photodynamic therapy (PDT) efficacy. Photophysiochemical properties of complexes 2, 3, and their conjugates (2-FA-NGQDs, 3-FA-NGQDs) were studied. It was found that complex 3 had higher Ï•Δ of 0.56 compared to complex 2 with Ï•Δ of 0.24, and respective composites: 3-FA-NGQDs had higher Ï•Δ compared to 2-FA-NGQDs. The PDT studies were conducted for nanoparticles (FA-NGQDs), complexes (2, 3), and respective composites (2-FA-NGQDs, and 3-FA-NGQDs) using MCF-7 breast cancer cell. Dark toxicity of all compounds was above 90% which is negligible. At a highest concentration of 40 µg/mL, 3-FA-NGQDs gave the lowest cell viability of 28% compared to all other conjugates and porphyrins alone.

Electrochemical detection of human epidermal growth factor receptor 2 using an aptamer on cobalt phthalocyanines - Cerium oxide nanoparticle conjugate.

The role of the biointerface design towards the development of an impedimetric biosensor for the electrochemical detection of human epidermal growth factor receptor 2 (HER2) is investigated. Two novel cobalt phthalocyanines: cobalt tetraphenyl acetic acid phthalocyanine and cobalt tetraphenyl propionic acid phthalocyanine are compared as signal amplifiers and immobilization platforms of the HB5 aptamer towards the electrochemical detection of HER2. In addition, the phthalocyanines are coupled with the metal based cerium oxide nanoparticles. The efficiency of each electrode modification step and the performance of the constructed aptasensors were assessed by impedance spectroscopy. The aptasensors showed very low limit of detection values (all less than 0.2 ng/mL) with high sensitivity and stability. Furthermore, the aptasensors showed very good performance even in human serum samples. Considering these results, the aptasensors demonstrate great potential for improved monitoring of human epidermal growth factor receptor 2 levels for the management of breast cancers.

Photodynamic Antitumor and Antimicrobial Activities of Free-Base Tetra(4-methylthiolphenyl)chlorin and Its Tin(IV) Complex.

Meso-tetra(4-methylthiolphenyl)chlorin (3) and its Sn(IV) complex (3-Sn) have been synthesized and characterized. The heavy atom effects of the Sn(IV) ion and sulfur atoms result in relatively high singlet oxygen quantum yield values of 0.40 and 0.48. The photodynamic activities against MCF-7 breast cancer cells were determined through irradiation with a Thorlabs 660 nm LED for 30 min (280 mW.cm-2 ). IC50 values of 7.8 and 3.9 µM were obtained, respectively. 3-Sn was found to have significant photodynamic antimicrobial activity against both gram-(+) S. aureus and gram-(-) E. coli bacteria upon irradiation with a Thorlabs 660 nm LED for 75 min.

Ultrasensitive detection of prostate-specific antigen using glucose-encapsulated nanoliposomes anti-PSA polyclonal antibody as detection nanobioprobes.

In this work, the preparation of glucose encapsulating nanoliposomes was achieved using two different lipid formulations, labelled as F1 and F2. Both formulations contained phosphatidylcholine (PC), oleylamido-4-butanoic acid (OABA) and in addition, F1 had cholesterol (CHO) while F2 contained cholesteroyl hemisussinate (CHEMS). These formulations were studied for their pH sensitivity and controlled release of encapsulated glucose for indirect detection of prostate-specific antigen (PSA) using sandwich immunoassay. As a signal generator, encapsulated glucose in nanoliposomes was quantified directly using the personal glucose meter (PGM) and colorimetrically using peroxidase property of horseradish peroxidase (HRP) enzyme and Pd|PdO as nanozymes. Controlled release of the encapsulated glucose was achieved using the pH effect or Triton-X 100 as a surfactant to destabilize the liposomal structure. The F2 formulation showed maximum controlled release at acidic phosphate buffer saline (PBS, pH 5.0). The concentration of encapsulated glucose was found to be high in F2 formulation and these were applied for the indirect detection of PSA. The limit of detection (LOD) values for PSA were found to be 53 fg mL-1, 64 fg mL-1 and 10 fg mL-1 when HRP, Pd|PdO and PGM were respectively used. The detection signal was linear over a wide concentration range for PSA including the clinical range of 4-10 ng mL-1. The HRP system showed low LOD value when compared with Pd|PdO nanozymes. PGM system gave lowest LOD values owing to the sensitivity of the system towards glucose. Pd|PdO nanozyme system showed good stability over a wide temperature up to 80 °C. PGM system required less reaction time (2 min), low reagents and results were readily generated in digital format.

Novel cationic-chalcone phthalocyanines for photodynamic therapy eradication of S. aureus and E. coli bacterial biofilms and MCF-7 breast cancer.

New tetrasubstituted zinc (II) and indium (III) phthalocyanines bearing dimethylamino chalcone group (complexes 3 and 4) as well as their quaternized analogs (3a and 4a) have been assessed for their photodynamic therapy (PDT) of cancer as well as photodynamic antimicrobial chemotherapy activities against biofilms and planktonic cultures of pathogenic bacteria of Staphylococcus aureus and Escherichia coli. Compared to the non-quaternized phthalocyanines 3 and 4, the cationic phthalocyanines 3a and 4a exhibit a higher photodynamic inactivation against the planktonic cells with log reduction values above 9 at a concentration of 1.25 µM. This was attributed to the positive charge which enhances cellular uptake. More interestingly, 3a and 4a show a higher photodynamic inactivation (less than 3% of S. aureus survived) on their biofilm counterparts thanks to their stronger affinity to these cells. 3a and 4a Pcs also exhibited interesting PDT activity against MCF-7 cancer cells giving IC50 values of 17.9 and 7.4 µM, respectively following 15 min irradiation. The obtained results in this work show that the positively charged phthalocyanines 3a and 4a are potential antibacterial photosensitizers that show some selectivity toward the Gram-positive and Gram-negative bacteria as well as MCF-7 breasts cancer cells.