Phthalocyanines as photodynamic agents for the inactivation of microbial pathogens

A variety of 1,8(11),15(18),22(25)- and 2,9(10),16(17),23(24)-tetra-substituted and 2,3,9,10,16,17,23,24-octa-susbtituted Zn (II) phthalocyanines, bearing dialkylaminophenoxy and trialkylammoniumphenoxy groups, have been synthetized, characterized and tested as photosensitizers against S. aureus, E. coli and C. albicans. All phthalocyanines exhibited intense absorption bands in the phototherapeutically useful 670-700 nm region, with a molar extinction coefficient of the order of 105 M-1.cm-1. All derivatives bearing positive charges showed a good photosensitizing efficiency (causing a greater than 4 log reduction in cell survival), as well as a high quantum yield for generation of singlet oxygen. Variations of the chemical structure appeared to strongly affect both the physicochemical properties and the phototoxic activities against microorganisms.

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Reduction of Microbial Pathogens during Apple Cider Production Using Sodium Hypochlorite, Copper Ion, and Sonication

Journal of Food Protection ◽

10.4315/0362-028x-67.4.766 ◽

2004 ◽

Vol 67 (4) ◽

pp. 766-771 ◽

Cited By ~ 25

Author(s):

STEPHANIE L. RODGERS ◽

ELLIOT T. RYSER

Keyword(s):

Sodium Hypochlorite ◽

Copper Ion ◽

Microbial Pathogens ◽

Sodium Hypochlorite Solution ◽

Escherichia Coli O157 ◽

Hypochlorite Solution ◽

Apple Cider ◽

E Coli ◽

Log Reduction ◽

Pathogen Reduction

Sodium hypochlorite (100 ppm), copper ion water (1 ppm), and sonication (22 to 44 kHz and 44 to 48 kHz) were assessed individually and in combination for their ability to reduce populations of Escherichia coli O157:H7 and Listeria monocytogenes on apples and in apple cider. Commercial unpasteurized cider was inoculated to contain approximately 106 CFU/ml of either pathogen and then sonicated at 44 to 48 kHz, with aliquots removed at intervals of 30 to 60 s for up to 5 min and plated to determine numbers of survivors. Subsequently, whole apples were inoculated by dipping to contain approximately 106 CFU/g E. coli O157:H7 or L. monocytogenes, held overnight, and then submerged in 1 ppm copper ion water with or without 100 ppm sodium hypochlorite for 3 min with or without sonication at 22 to 44 kHz and examined for survivors. Treated apples were also juiced, with the resulting cider sonicated for 3 min. Populations of both pathogens decreased 1 to 2 log CFU/ml in inoculated cider following 3 min of sonication. Copper ion water alone did not significantly reduce populations of either pathogen on inoculated apples. However, when used in combination with sodium hypochlorite, pathogen levels decreased approximately 2.3 log CFU/g on apples. Sonication of this copper ion–sodium hypochlorite solution at 22 to 44 kHz did not further improve pathogen reduction on apples. Numbers of either pathogen in the juice fraction were approximately 1.2 log CFU/ml lower after being juiced, with sonication (44 to 48 kHz) of the expressed juice decreasing L. monocytogenes and E. coli O157:H7 populations an additional 2 log. Hence, a 5-log reduction was achievable for both pathogens with the use of copper ion water in combination with sodium hypochlorite followed by juicing and sonication at 44 to 48 kHz.

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Double labelling of intracellular mitochondria and nucleolus using thiophene pyridium salt with high quantum yield as biosensor and its application in stimulated emission depletion nanoscopy

Analytica Chimica Acta ◽

10.1016/j.aca.2017.12.033 ◽

2018 ◽

Vol 1008 ◽

pp. 82-89 ◽

Cited By ~ 1

Author(s):

Xiaohe Tian ◽

Hui Wang ◽

Qiong Zhang ◽

Mingzhu Zhang ◽

Yingzhong Zhu ◽

...

Keyword(s):

Quantum Yield ◽

Stimulated Emission ◽

Double Labelling ◽

High Quantum Yield ◽

High Quantum ◽

Stimulated Emission Depletion

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Superior Stable and High Quantum Yield Phosphor Na2BaSr(PO4)2: Eu2+ for Plant Growth LEDs

Materials Chemistry Frontiers ◽

10.1039/d1qm00671a ◽

2021 ◽

Author(s):

Jinmeng Xiang ◽

Xiaoqi Zhao ◽

Hao Suo ◽

Minkun Jin ◽

Xue Zhou ◽

...

Keyword(s):

Quantum Yield ◽

Plant Growth ◽

Light Emitting Diodes ◽

Light Environment ◽

High Quantum Yield ◽

Light Emitting ◽

Growth Rhythm ◽

High Quantum ◽

Violet Light ◽

Important Means

Controlling the light environment of plant growth using phosphor-converted light-emitting diodes (pc-LEDs) is an important means to regulate the growth rhythm and enhance the yield, in which bluish violet light...

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