Tailoring Graphene Quantum Dots through the Pyrolysis of Citric Acid, Phenylalanine, and Tryptophan: Effect  of Precursor Ratios on Synthesis Efficiency and Properties

Recep Üzek

Makale detayları

Tailoring Graphene Quantum Dots through the Pyrolysis of Citric Acid, Phenylalanine, and Tryptophan: Effect of Precursor Ratios on Synthesis Efficiency and Properties

Yazarlar:

Recep Üzek

Yayıncı:

Hitit University

Ana Başlıklar:

Functional Materials | Material Characterization

Dergi:

Hittite Journal of Science and Engineering Vol.12 Issue 3, pp.121-127

Belge Tipi:

Makale

Yayın Tarihi:

9/2025

Belge Dili:

İngilizce

Document ID (Org No.):

2001359127

pISSN:

2148-4171

Anahtar kelimeler:

Özet:

 Graphene Quantum Dots GQDs are gaining significant attention due to their unique optical, electronic, and biocompatible properties, making them ideal candidates for applications in bioimaging, sensing, and drug delivery. This study explores the synthesis of GQDs derived from citric acid CA, phenylalanine Phe, and tryptophan Trp using a pyrolysis method, where GQDs were synthesized using 2.0 g of CA with varying amounts of Phe 0.75 g, 0.50 g, 0.25 g and Trp 0.25 g, 0.50 g, 0.75 g, corresponding to GQDs1, GQDs2, and GQDs3, respectively. The influence of precursor composition on the structural, optical, and physicochemical properties of GQDs was analyzed. Particle size measurements showed a hydrodynamic diameter range of 0.89 nm to 1.5 nm, with increasing Trp content leading to larger particles and a broader size distribution, reflected in polydispersity index PDI values of 0.221, 0.312, and 0.368 for GQDs1, GQDs2, and GQDs3, respectively. Zeta potential analysis revealed values of -21.4 mV, -12.2 mV, and -7.5 mV for GQDs1, GQDs2, and GQDs3, respectively, indicating reduced surface charge with higher Trp content, which may affect colloidal stability. Optical characterization showed ππ 230270 nm and nπ 300350 nm transitions in the UV-Vis spectra, with varying absorbance intensities across samples. Fluorescence spectroscopy confirmed strong emission properties, which were highly dependent on precursor ratios. Quantum yield QY values were 32.2, 95.5, and 75.6 for GQDs1, GQDs2, and GQDs3, respectively, highlighting the role of nitrogen doping in fluorescence enhancement. These findings demonstrate that controlled precursor composition can fine-tune GQD properties, offering potential for optoelectronic, bioimaging, and sensing applications. Further exploration of functionalization strategies could enhance their practical utility.

 Graphene Quantum Dots GQDs are gaining significant attention due to their unique optical, electronic, and biocompatible properties, making them ideal candidates for applications in bioimaging, sensing, and drug delivery. This study explores the synthesis of GQDs derived from citric acid CA, phenylalanine Phe, and tryptophan Trp using a pyrolysis method, where GQDs were synthesized using 2.0 g of CA with varying amounts of Phe 0.75 g, 0.50 g, 0.25 g and Trp 0.25 g, 0.50 g, 0.75 g, corresponding to GQDs1, GQDs2, and GQDs3, respectively. The influence of precursor composition on the structural, optical, and physicochemical properties of GQDs was analyzed. Particle size measurements showed a hydrodynamic diameter range of 0.89 nm to 1.5 nm, with increasing Trp content leading to larger particles and a broader size distribution, reflected in polydispersity index PDI values of 0.221, 0.312, and 0.368 for GQDs1, GQDs2, and GQDs3, respectively. Zeta potential analysis revealed values of -21.4 mV, -12.2 mV, and -7.5 mV for GQDs1, GQDs2, and GQDs3, respectively, indicating reduced surface charge with higher Trp content, which may affect colloidal stability. Optical characterization showed ππ 230270 nm and nπ 300350 nm transitions in the UV-Vis spectra, with varying absorbance intensities across samples. Fluorescence spectroscopy confirmed strong emission properties, which were highly dependent on precursor ratios. Quantum yield QY values were 32.2, 95.5, and 75.6 for GQDs1, GQDs2, and GQDs3, respectively, highlighting the role of nitrogen doping in fluorescence enhancement. These findings demonstrate that controlled precursor composition can fine-tune GQD properties, offering potential for optoelectronic, bioimaging, and sensing applications. Further exploration of functionalization strategies could enhance their practical utility.

 Graphene Quantum Dots GQDs are gaining significant attention due to their unique optical, electronic, and biocompatible properties, making them ideal candidates for applications in bioimaging, sensing, and drug delivery. This study explores the synthesis of GQDs derived from citric acid CA, phenylalanine Phe, and tryptophan Trp using a pyrolysis method, where GQDs were synthesized using 2.0 g of CA with varying amounts of Phe 0.75 g, 0.50 g, 0.25 g and Trp 0.25 g, 0.50 g, 0.75 g, corresponding to GQDs1, GQDs2, and GQDs3, respectively. The influence of precursor composition on the structural, optical, and physicochemical properties of GQDs was analyzed. Particle size measurements showed a hydrodynamic diameter range of 0.89 nm to 1.5 nm, with increasing Trp content leading to larger particles and a broader size distribution, reflected in polydispersity index PDI values of 0.221, 0.312, and 0.368 for GQDs1, GQDs2, and GQDs3, respectively. Zeta potential analysis revealed values of -21.4 mV, -12.2 mV, and -7.5 mV for GQDs1, GQDs2, and GQDs3, respectively, indicating reduced surface charge with higher Trp content, which may affect colloidal stability. Optical characterization showed ππ 230270 nm and nπ 300350 nm transitions in the UV-Vis spectra, with varying absorbance intensities across samples. Fluorescence spectroscopy confirmed strong emission properties, which were highly dependent on precursor ratios. Quantum yield QY values were 32.2, 95.5, and 75.6 for GQDs1, GQDs2, and GQDs3, respectively, highlighting the role of nitrogen doping in fluorescence enhancement. These findings demonstrate that controlled precursor composition can fine-tune GQD properties, offering potential for optoelectronic, bioimaging, and sensing applications. Further exploration of functionalization strategies could enhance their practical utility.

 Graphene Quantum Dots GQDs are gaining significant attention due to their unique optical, electronic, and biocompatible properties, making them ideal candidates for applications in bioimaging, sensing, and drug delivery. This study explores the synthesis of GQDs derived from citric acid CA, phenylalanine Phe, and tryptophan Trp using a pyrolysis method, where GQDs were synthesized using 2.0 g of CA with varying amounts of Phe 0.75 g, 0.50 g, 0.25 g and Trp 0.25 g, 0.50 g, 0.75 g, corresponding to GQDs1, GQDs2, and GQDs3, respectively. The influence of precursor composition on the structural, optical, and physicochemical properties of GQDs was analyzed. Particle size measurements showed a hydrodynamic diameter range of 0.89 nm to 1.5 nm, with increasing Trp content leading to larger particles and a broader size distribution, reflected in polydispersity index PDI values of 0.221, 0.312, and 0.368 for GQDs1, GQDs2, and GQDs3, respectively. Zeta potential analysis revealed values of -21.4 mV, -12.2 mV, and -7.5 mV for GQDs1, GQDs2, and GQDs3, respectively, indicating reduced surface charge with higher Trp content, which may affect colloidal stability. Optical characterization showed ππ 230270 nm and nπ 300350 nm transitions in the UV-Vis spectra, with varying absorbance intensities across samples. Fluorescence spectroscopy confirmed strong emission properties, which were highly dependent on precursor ratios. Quantum yield QY values were 32.2, 95.5, and 75.6 for GQDs1, GQDs2, and GQDs3, respectively, highlighting the role of nitrogen doping in fluorescence enhancement. These findings demonstrate that controlled precursor composition can fine-tune GQD properties, offering potential for optoelectronic, bioimaging, and sensing applications. Further exploration of functionalization strategies could enhance their practical utility.

Makale detayları

Tailoring Graphene Quantum Dots through the Pyrolysis of Citric Acid, Phenylalanine, and Tryptophan: Effect of Precursor Ratios on Synthesis Efficiency and Properties

Yazarlar:

Recep Üzek

Yayıncı:

Hitit University

Ana Başlıklar:

Functional Materials | Material Characterization

Dergi:

Hittite Journal of Science and Engineering Vol.12 Issue 3, pp.121-127

Belge Tipi:

Makale

Yayın Tarihi:

9/2025

Belge Dili:

İngilizce

Document ID (Org No.):

2001359127

pISSN:

2148-4171

graphene quantum dots

pyrolysis

quantum yield

fluorescence

Sayı

Makale detayları

Tailoring Graphene Quantum Dots through the Pyrolysis of Citric Acid, Phenylalanine, and Tryptophan: Effect of Precursor Ratios on Synthesis Efficiency and Properties

Yazarlar: Recep Üzek

Yayıncı: Hitit University

Ana Başlıklar: Functional Materials | Material Characterization

Dergi: Hittite Journal of Science and Engineering Vol.12 Issue 3, pp.121-127

Belge Tipi: Makale

Yayın Tarihi: 9/2025

Belge Dili: İngilizce

Document ID (Org No.): 2001359127

pISSN: 2148-4171

graphene quantum dots

pyrolysis

quantum yield

fluorescence

Sayı

Yazarlar:

Recep Üzek

Yayıncı:

Hitit University

Ana Başlıklar:

Functional Materials | Material Characterization

Dergi:

Hittite Journal of Science and Engineering Vol.12 Issue 3, pp.121-127

Belge Tipi:

Makale

Yayın Tarihi:

9/2025

Belge Dili:

İngilizce

Document ID (Org No.):

2001359127

pISSN:

2148-4171