Continuous rotation of the surface target during laser ablation, as depicted in Fig. 2, distributes the large colloidal particle formed in the solution and prevents the agglomeration process due to further interaction with the laser beam. The generated Au particles are collected in the middle of the solution and can readily undergo laser irradiation synthesis before dispersing throughout the medium once the rotational stage stops. The fitting parameters are reported in Table 2. The SPA maximums were seen to be sharply located around 520 nm and slightly enhanced toward the shorter spectral region. The ratio of the absorbance at different wavelengths () can be used to quantitatively monitor the aggregation principal without knowledge of the particle size and concentration.12 The absorption spectra beyond 600 nm are exclusively attributed to the existence of a small amount of oblate particles. Higher values of the ratios possess a lower agglomeration definition between the generated particles. As the rotational speed increases, larger particles are fragmented into smaller ones by the Coulomb explosion that leads to an average radius below 5 nm in size. On the other hand, the lower value of reflects the small fraction of the spheroidal contributions. The finding suggests that the aggregation and reshaping of the AuNPs are considered to be induced by photoexcitation followed by the melting of the NPs based on the laser-liquid interaction.13 A linear relationship between the contributions of the spheroidal particles and the rotational speed was obtained as shown in the inset of Fig. 2. These indicate the lower contribution of the spheroidal particles and a much greater contribution from smaller sphere particles oscillating near the surface plasmon resonance of the local electromagnetic field. Figure 3 shows a clearer view of the absorption spectrum of AuNPs stationary both stationary (0 RPM) and rotating at 80 RPM with respect to Fig. 2(b), together with the EFTEM image. The filled area under the graph illustrates the contribution of spherical and spheroidal particles in the solution, respectively. For 0 RPM, shown in Fig. 3(a), the Mie–Gans fitting built on the summation of both shape contributions demonstrates an average radius of in accordance with the spheroid’s contributions of 34%. When observing the corresponding electron micrograph, the AuNPs were seen overlapping among each other and showed the presence of cigar-like particle shapes made by several closely bound aggregated particles. As specified by the TEM analysis, the mean radius and standard deviation calculated from the log-normal distribution are . This is in good agreement with the Mie–Gans calculation. The optimal maximum speed was determined at 80 RPM. Mie–Gans calculation traces with a smaller average radius of for the fraction of spheroidal particles significantly diminished to 20% after the laser treatment, as shown in Fig. 3(b). This led to the low absorbance above the 600 nm spectral range. Furthermore, the size distribution of AuNPs tends to shift to smaller radii after the rotation speed increases. The formation of the particles observed was well separated with respect to one another and revealed a more nearly spherical shape where the average radius and size distribution were calculated to be . This still provides remarkable agreement with the radius calculated with the Mie–Gans model. The results showed that at 0 RPM, the NPs were found to aggregate, whereas at the higher rotational speed of 80 RPM, they were found to be reduced in size and exhibited a narrower size distribution as well as a larger number of smaller NP particles within the solution. The better size separation offers a lower degree of polydispersity (15.5%) for a one-step AuNPs synthesis.