TY - JOUR

T1 - Near-Infrared Photothermal Efficient Ge Nanoparticles Synthesized via Nanosecond Laser Ablation in Liquid

AU - Gurbatov, S.O.

AU - Banniy, D.E.

AU - Shevlyagin, A.V.

AU - Kuchmizhak, A.A.

N1 - Export Date: 09 March 2026; Cited By: 0; Correspondence Address: A.V. Shevlyagin; Institute of Automation and Control Processes, Far Eastern Branch, Russian Academy of Sciences, Vladivostok, 690041, Russian Federation; email: shevlyagin@iacp.dvo.ru

PY - 2025

Y1 - 2025

N2 - Abstract: We have explored germanium nanoparticles (Ge NPs) as a potential material for photothermal therapy in cancer treatment. Given the high intrinsic optical absorption of bulk germanium in the near-infrared (NIR-I) biological transparency window, pulsed laser ablation in liquid (PLAL) was employed to produce a colloid of Ge NPs with a Mie-resonant size in the range of 100–500 nm. The heating efficiency of individual Ge NPs was evaluated using 785 nm laser irradiation, while the temperature-dependent shift in the Ge–Ge Raman band was monitored simultaneously. The maximum estimated temperature increase of 480 K at a laser power density of 3 mW/μm2 for Ge NPs with a diameter of 300 nm was confirmed with no signs of oxidation or structural degradation. This value is more than four times higher than that of pure silicon NPs of a similar size. Laser heating (808 nm, 4.5 W) of an isopropanol suspension containing Ge NPs demonstrated that their resonant size enables grounds for mild photothermal therapy with a linear light-to-heat conversion efficiency response to NPs concentration reaching 17%, and the potential to heat the suspension by ∆T = 5–50°C within an NPs concentration range of 1.25–10 μg/mL. © Pleiades Publishing, Ltd. 2025.

AB - Abstract: We have explored germanium nanoparticles (Ge NPs) as a potential material for photothermal therapy in cancer treatment. Given the high intrinsic optical absorption of bulk germanium in the near-infrared (NIR-I) biological transparency window, pulsed laser ablation in liquid (PLAL) was employed to produce a colloid of Ge NPs with a Mie-resonant size in the range of 100–500 nm. The heating efficiency of individual Ge NPs was evaluated using 785 nm laser irradiation, while the temperature-dependent shift in the Ge–Ge Raman band was monitored simultaneously. The maximum estimated temperature increase of 480 K at a laser power density of 3 mW/μm2 for Ge NPs with a diameter of 300 nm was confirmed with no signs of oxidation or structural degradation. This value is more than four times higher than that of pure silicon NPs of a similar size. Laser heating (808 nm, 4.5 W) of an isopropanol suspension containing Ge NPs demonstrated that their resonant size enables grounds for mild photothermal therapy with a linear light-to-heat conversion efficiency response to NPs concentration reaching 17%, and the potential to heat the suspension by ∆T = 5–50°C within an NPs concentration range of 1.25–10 μg/mL. © Pleiades Publishing, Ltd. 2025.

KW - colloid nanoparticles

KW - germanium

KW - Mie- resonance

KW - nanothermometry

KW - photo hyperthermia

KW - photothermal conversion

KW - pulsed laser ablation in liquid

KW - Conversion efficiency

KW - Germanium compounds

KW - Hyperthermia therapy

KW - Infrared devices

KW - Laser ablation

KW - Light absorption

KW - Nanoparticles

KW - Oncology

KW - Pulsed lasers

KW - Suspensions (fluids)

KW - Colloid nanoparticles

KW - Germaniums (Ge)

KW - Mie resonance

KW - Nanothermometry

KW - Near Infrared

KW - Near-infrared

KW - Photo hyperthermia

KW - Photothermal conversion

KW - Photothermal therapy

KW - Pulsed laser ablation in liquids

KW - Germanium

U2 - 10.1134/S1062873825714837

DO - 10.1134/S1062873825714837

M3 - статья

VL - 89

SP - S492-S498

JO - Bulletin of the Russian Academy of Sciences: Physics

JF - Bulletin of the Russian Academy of Sciences: Physics

SN - 1062-8738

IS - Suppl 4

ER -