Glucose decorated gold nanoclusters: A membrane potential independent fluorescence probe for rapid identification of cancer cells expressing Glut receptors.

The effective nanomedicines require nanoparticles to attach or adhere to the cell surface, which is dictated by several parameters of nanoparticles such as shape, size, charge, and composition. However, these parameters lead to the membrane potential dependent non-specific delivery of therapeutic or imaging nanosystems into cancer cells. This leads to significant complications and results into the serious impediment to effective treatment of cancer. Cancer cells are known to metabolize high amount of glucose in order to support their rapid proliferation and expansion. Recently, gold nanoclusters (AuNCs) have emerged as an excellent fluorescent nanoprobe for bio-imaging and related applications in cancer treatment. Therefore, taking cues from these studies, we have developed two types of gold nanoclusters, BSA-coated (BSA-AuNCs) and glucose coated gold nanoclusters (Glu-AuNCs) and investigated their mechanism of internalization in cell culture model systems of cancerous and noncancerous cells. Our study demonstrates that Glu-AuNCs are not internalized by HaCaT cells but selectively taken up by A431 cells through Glut-1 receptors, but their uptake was cell membrane potential independent. However, BSA-AuNCs showed more internalization in A431 than HaCaT cells, but their uptake was cell membrane potential dependent.