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<p>Synthesis of meso-tetra-(4-sulfonatophenyl) porphyrin (TPPS₄) – CuInS/ZnS quantum dots conjugate as an improved photosensitizer</p>

2019; Dove Medical Press; Volume: Volume 14; Linguagem: Inglês

10.2147/ijn.s211959

1178-2013

Ncediwe Tsolekile, Vuyelwa Ncapayi, Gabriel K. Obiyenwa, Mangaka C. Matoetoe, Sandile P. Songca, Oluwatobi S. Oluwafemi,

Nanoplatforms for cancer theranostics

Background: Metal-free, water-soluble and highly stable meso-tetra-(4-sulfonatophenyl) porphyrin (TPPS 4 ) has been studied for their singlet oxygen quantum yield. However, TPPS 4 suffers from inherent shortcomings. To address these, TPPS 4 was conjugated to ternary copper indium sulphide/ zinc sulphide (CuInS 2 /ZnS) quantum dots (QDs). Purpose: We herein report for the first time the synthesis of TPPS 4 –CuInS/ZnS QDs conjugate as an improved photosensitizer. Methods: Water-soluble TPPS 4 was synthesized from tetraphenylporphyrin (TPPH 2 ) after silica-gel purification. The CuInS/ZnS QDs were synthesized by hydrothermal method at a Cu:In ratio of 1:4. The porphyrin–QDs conjugate was formed via the daggling sulfonyl bond of the porphyrin and amine bond of the QDs. The effect of pH on the optical properties of TPPS 4 was evaluated. The effect of Zn:Cu + In ratio on the ZnS shell passivation was examined to reduce structural defects on the as-synthesized QDs. Results: Various spectroscopic techniques were used to confirm the successful conversion of the organic TPPH 2 to water-soluble TPPS 4 . The singlet oxygen generation evaluation shows an improved singlet oxygen quantum yield from 0.19 for the porphyrin (TPPS 4 ) alone to 0.69 after conjugation (CuInS/ZnS-TPPS 4 ) with an increase in the reaction rate constant (k (s-1)). Keywords: CuInS/ZnS, meso-tetra-(4-sulfonatophenyl) porphyrin, TTPS 4 , singlet oxygen, conjugation, quantum dots