Rajas Ketkar

Mr. Rajas Ketkar

orcid

Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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Journal Article
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RKRajas Ketkar
Rajas Ketkar
YLYue Liu
Yue Liu
HWHengji Wang
Hengji Wang
HTHao Tian
Hao Tian
With the wide usage of organic compounds, the assessment of their acute toxicity has drawn great attention to reduce animal testing and human labor. The development of graph models provides new opportunities for acute toxicity prediction. In this study, five graph models (message-passing neural network, graph convolution network, graph attention network, path-augmented graph transformer network, and Attentive FP) were applied on four toxicity tasks (fish, Daphnia magna, Tetrahymena pyriformis, and Vibrio fischeri). With the lowest prediction error, Attentive FP was reported to have the best performance in all four tasks. Moreover, the attention weights of the Attentive FP model helped to construct atomic heatmaps and provide good explainability.

10 October 2026 in Angewandte Chemie International Edition
Verified
Journal Article
Open access
PDF file
LWLionel Wettstein
Lionel Wettstein
AGAurelio C. Gasser
Aurelio C. Gasser
DKDaniel Käch
Daniel Käch
YPYanlin Pan
Yanlin Pan
JRJan Reger
Jan Reger
MBMáté J. Bezdek
Máté J. Bezdek
Light offers a powerful means of activating materials with spatial and temporal precision. However, translating excited‐state processes into chemically responsive electronic function in conductive solids remains challenging, particularly under low‐energy red illumination. Herein, we report red light‐gated charge transfer in dye‐sensitized single‐walled carbon nanotube–TiO 2 (SWCNT–TiO 2 ) hybrids that enables trace oxygen detection. Immobilization of red‐absorbing squaraine sensitizers on TiO 2 domains embedded within a conductive SWCNT network reversibly generates a photostationary charge‐transfer state under 628 nm excitation. Despite the low photon energy of red light, the hybrid architecture supports interfacial electron injection into TiO 2 and hole accumulation in the nanotube scaffold, while remaining electronically dormant in the dark. Interception of photogenerated electrons by O 2 perturbs this light‐induced state and converts excited‐state redox chemistry into a chemiresistive signal with ppb‐level sensitivity. This capability enables continuous monitoring of oxygen depletion in a sealed headspace during food spoilage. Electron paramagnetic resonance spectroscopy, energy‐level alignment analysis, and charge‐carrier inversion experiments show that O 2 triggers light‐activated changes in SWCNT carrier density. These findings demonstrate that low‐energy optical excitation can gate chemical response in dye‐sensitized SWCNT–TiO 2 hybrids, establishing a design strategy for temporally controlled sensing and photoresponsive electronic function.

10 October 2026 in Angewandte Chemie
Verified
Journal Article
Open access
LWLionel Wettstein
Lionel Wettstein
AGAurelio C. Gasser
Aurelio C. Gasser
DKDaniel Käch
Daniel Käch
YPYanlin Pan
Yanlin Pan
JRJan Reger
Jan Reger
MBMáté J. Bezdek
Máté J. Bezdek
Light offers a powerful means of activating materials with spatial and temporal precision. However, translating excited‐state processes into chemically responsive electronic function in conductive solids remains challenging, particularly under low‐energy red illumination. Herein, we report red light‐gated charge transfer in dye‐sensitized single‐walled carbon nanotube–TiO 2 (SWCNT–TiO 2 ) hybrids that enables trace oxygen detection. Immobilization of red‐absorbing squaraine sensitizers on TiO 2 domains embedded within a conductive SWCNT network reversibly generates a photostationary charge‐transfer state under 628 nm excitation. Despite the low photon energy of red light, the hybrid architecture supports interfacial electron injection into TiO 2 and hole accumulation in the nanotube scaffold, while remaining electronically dormant in the dark. Interception of photogenerated electrons by O 2 perturbs this light‐induced state and converts excited‐state redox chemistry into a chemiresistive signal with ppb‐level sensitivity. This capability enables continuous monitoring of oxygen depletion in a sealed headspace during food spoilage. Electron paramagnetic resonance spectroscopy, energy‐level alignment analysis, and charge‐carrier inversion experiments show that O 2 triggers light‐activated changes in SWCNT carrier density. These findings demonstrate that low‐energy optical excitation can gate chemical response in dye‐sensitized SWCNT–TiO 2 hybrids, establishing a design strategy for temporally controlled sensing and photoresponsive electronic function.