Single‐Step Reagentless Laser Scribing Fabrication of Electrochemical Paper‐Based Analytical Devices

A single‐step laser scribing process is used to pattern nanostructured electrodes on paper‐based devices. The facile and low‐cost technique eliminates the need for chemical reagents or controlled conditions. This process involves the use of a CO₂ laser to pyrolyze the surface of the paperboard, producing a conductive porous non‐graphitizing carbon material composed of graphene sheets and composites with aluminosilicate nanoparticles. The new electrode material was extensively characterized, and it exhibits high conductivity and an enhanced active/geometric area ratio; it is thus well‐suited for electrochemical purposes. As a proof‐of‐concept, the devices were successfully employed for different analytical applications in the clinical, pharmaceutical, food, and forensic fields. The scalable and green fabrication method associated with the features of the new material is highly promising for the development of portable electrochemical devices.     

Conformational SERS Classification of K‐Ras Point Mutations for Cancer Diagnostics

Point mutations in Ras oncogenes are routinely screened for diagnostics and treatment of tumors (especially in colorectal cancer). Here, we develop an optical approach based on direct SERS coupled with chemometrics for the study of the specific conformations that single‐point mutations impose on a relatively large fragment of the K‐Ras gene (141 nucleobases). Results obtained offer the unambiguous classification of different mutations providing a potentially useful insight for diagnostics and treatment of cancer in a sensitive, fast, direct and inexpensive manner.