430 Nanosensors: Physical, Chemical, and Biological
signal). (iii) Sample preparation is in itself an elaborate and intricate pre-
paratory step for any analysis. Samples need to be made in pure water or
accurately controlled salt solutions
What is the solution to the problem? A matrix-independent method is neces-
sary. A general sensing platform that can be ubiquitously applied to detect
the constellation of biomolecules in varied clinical samples (e.g., serum, urine,
cell lysates, or saliva) with high sensitivity and large linear dynamic range is
the answer to the problem. The additional advantage is that the matrices of
even the most complex biological samples lack a detectable magnetic back-
ground signal and produce no interference with