Barcode-integrated cellulose based microfluidic system for intelligent point-of-care blood typing

Accurate and rapid blood typing plays a critical role in life-saving clinical procedures such as blood transfusions and organ transplantation. Herein, we proposed a novel blood typing system (BloodStrips) that combines cellulose based microfluidics with universal barcode technology, achieving intelligent, rapid, and user-friendly blood type detection. The BloodStrips system employed heat transfer printing to create barcode patterns on hydrophobic cotton substrates and integrated cotton threads to construct hydrophilic channels. Meanwhile, the swinging elution method was harnessed to remove free red blood cells (RBCs) while retaining aggregated RBCs on the cotton threads, thereby resulting in creating a distinct white/red contrast at the macro level (white represents cotton thread, red represents bloodstain). The white/red barcodes with different combinations were used to represent various blood types. Based on this principle, we further developed a portable and automated blood tying chip called the BloodBar chip. It is worth noting that this device leverages a simple and straightforward smartphone scanning technique to decipher blood types, avoiding reading errors caused by ambient light intensity and personal bias. This work provides a universal and intelligent visual diagnostic platform for simple, rapid, and accurate blood typing, which may find wide applications in developing countries or resource-limited areas.