Fluorescence-guided surgery has emerged as a transformative technique in neurosurgical oncology, particularly for distinguishing malignant tissues from healthy neural structures during brain tumor resections. This approach aids in enhancing surgical precision and improving patient outcomes. In this study, the effectiveness of a novel near-infrared carbocyanine dye, SIDAG, was evaluated. SIDAG was designed to improve the contrast between tumor tissues and surrounding healthy neural tissue, allowing for better visualization during surgery. The research included experiments with two cell lines: the GBM–8401 cell line, representing glioblastoma multiforme (GBM) cells, and the SK-N-MC cell line, representing neuroblastoma cells that resemble neuron-like structures. Initial findings demonstrated that SIDAG exhibits good biocompatibility and preferential binding to neuron-like cells, suggesting its potential for real-time, high-resolution imaging in surgical settings. These results highlight SIDAG’s ability to help neurosurgeons more accurately differentiate between malignant and healthy tissues, enabling more precise tumor resections while minimizing the risk of damaging critical neural structures. The incorporation of SIDAG into fluorescence-guided surgery holds the promise of significantly reducing post-operative neurological deficits, improving surgical outcomes, and accelerating patient recovery. This advancement could ultimately reshape the landscape of neurosurgical treatment for brain tumors, providing better long-term results for patients.