Facile fabrication of biocompatible carbon dots from egg white by one-step neutralization heat reaction: A capillary array-based fluorimetric strategy for high-throughput detection of total iron ions in fish blood

Water-soluble and biocompatible protein carbon dots (P-CDs) were prepared from egg white simply by the rapid one-step reaction of neutralization heat reaction. Unexpectedly, the so fabricated P-CDs could present the excitation-dependent tunable fluorescence that could be quenched specifically by Fe3+ and Fe2+ ions with obvious color changes. A high-throughput fluorimetric platform was thereby developed by coating the P-CDs onto the capillary array for detection of total iron ions in fish blood samples, with the linear concentration range of 0.25-60.00 μM and the detection limit of 0.085 μM. Moreover, it can allow for the fast evaluation of total iron ions in fish blood samples, showing the recovery efficiencies of 97.25%-99.84%. Such a facile fabrication route for P-CDs from egg white by the rapid neutralization reaction may open a new door for preparing different CDs. More importantly, the developed fluorimetric method may be expected for the wide applications in the fields of diagnosis of iron-relative diseases, monitoring of environmental water, and ensuring of aquatic product safety.