Table 2. Comparative study on various gold nanoparticles-mediated photothermal and photodynamic therapy.

Type of gold	Laser treatment	Cell model	Application	Outcomes	Advantages
Gold nanorods	808 nm laser (0.5 W cm−2), 60 s	Human liver cancer HepG2 cells	PTT	When more MMP-9 was added, the ensuing responsive AuNRs displayed much greater cellular uptake in vitro136	Experimentally, AuNRs are effective cancer treatments because they penetrate and retain tumour tissue better than normal tissue. The aspect ratio of AuNRs influences tumour retention. Despite the fact that smaller AuNRs are eliminated faster, high aspect ratio and small volume AuNRs are ideal for tumour-mediated transport employing the EPR effect. AuNRs circulate longer than nanospheres, and macrophages absorb them four times better137,138
Gold nanorods	633 nm and 808 nm	Rats, 8 to 10 weeks in age	PDT & PTT	The combination of PDT + PTT therapy caused a significant reduction in tumor volume and large-area tumor necrosis139
Gold nanocages	805 nm	The breast cancer cell line SK-BR-3	PTT	We have shown that Au nanocages with comparable optical characteristics may effectively act as agents for the in vitro photothermal killing of cancer cells140	Photothermal conversion is enhanced by gold nanocages, a novel nanoparticle. The average size is 20–50 nm. A galvanic replacement reaction with a silver template and gold salt creates a hollow gold–silver alloy structure with variable wall thickness. The nanocage's surface develops a gold coating due to the metals' differing chemical potentials, while silver ions dissolve into the aqueous HAuCl4 solution. Gold nanocages' porous surface and hollow interior make them promising for medication delivery and encapsulation. Gold nanocages passively and actively distribute medications by upregulating cancer cell receptors and increasing EPR141
Gold nanocages	580 and 630 nm 2.5 W cm−2	HeLa cells	PDT	We saw increased cell death when HeLa cells were exposed to 630 nm light and cultured with nanocomposites142
Gold nanospheres	808 nm at an output power of 32 W cm−2 for 3 min	B16/F10 melanoma cells	PTT	NDP-MSH-PEG-HAuNS have the potential to mediate targeted photothermal ablation of melanoma143	The internalisation and membrane wrapping of spherical particles have been extensively explored. Continuous wrapping, low adhesion energy, and low membrane energy barriers make spherical particles easier to absorb than nonspherical ones144
Gold nanoshell	820 nm, 35 W cm−2	Human breast carcinoma	PTT	When human breast cancer cells cultured with nanoshells were exposed to NIR light (820 nm, 35 W cm−2), it was discovered that photothermally caused morbidity145	Gold nanoshells (AuNSs) are nanoparticles with a gold coating on an inorganic (metal) or organic (polymer or lipid) core. Their unique features make them popular in medicine delivery. First, their resonance optical properties enable deep tissue penetration and rely on size and shape. They also absorb light and convert it into heat for photothermal ablation of cancer cells. AuNSs may release drugs at precise places when subjected to near-infrared (NIR) radiation. By functionalising these particles with ligands, they can connect to sick cell receptors for precise targeting. AuNSs are ideal for passive drug delivery because they accumulate in tumours via the enhanced permeability and retention (EPR) effect. Encasing nucleic acids, protecting them from degradation, and releasing them precisely by NIR irradiation, AuNSs may be employed in gene therapy146
Gold nanoshell	670 nm (PDT) and λ = 810 nm	Head and neck carcinoma	PDT	In NIR irradiance, we observed significant cell inhibition at PDT radiant doses 80–100 times lower than those necessary for comparable outcomes with dual-function nanosystems147
Gold nanoflower	808 nm (9 W cm−2) for 5 minutes	HeLa cells	PTT	This kind of AuNF was shown to be non-toxic to HeLa cells when exposed to visible light, but NIR irradiation in vitro significantly increased photothermal ablation148	Gold nanoflower has low toxicity to cells, and a strong photothermal effect148
Gold nanoring	1064 nm, 200 mW	Oral cancer cells	PTT & PDT	By using the Au NP sample to compare the inactivation threshold intensities of NRI between fs and CW laser illuminations, we can see that fs laser illumination is more effective in cancer cell inactivation through the PTT effect when compared with CW laser illumination149	Gold nanoring has a deeper tissue penetration149