Single-walled carbon nanotubes (SWCNTs) are an emerging building block for nanoscale sensors and labels because of their unique photophysical properties. Semiconducting SWCNTs fluoresce in the tissue transparency near infrared (nIR) window (840 – 1650 nm) and do not bleach. Due to their 1D nature small perturbations in their environment strongly affect their fluorescence. The major challenges in using SWCNTS for sensing is on the one side their purification and on the other side a tailored surface chemistry for molecular recognition and photophysical signal transduction.Here, we present different approaches to tailor SWCNT surface chemistry and fluorescence emission properties for the detection of biologically important metabolites. Firstly, we tuned the sensitivity of ssDNA/SWCNTs against the neurotransmitter dopamine and different plant polyphenols by changing systematically the DNA sequence. In a more rational approach, we engineered DNA strands conjugated to small peptide sequences. In order to enable a ratio-specific linkage, we determined the amount of bound DNA on the SWCNT surface, which was further observed to play an important role in maintaining colloidal stability of the modified ssDNA/SWCNT conjugates. Finally, aptamer-based approaches were used to combine stable surface modification with target selective binding. For all these approaches we demonstrated via nIR-fluorescence spectroscopy and nIR-fluorescence stand-off imaging that tailoring these nanosensors resulted in an increased specificity against their targets, ranging from small chemical communication compounds (dopamine, H2O2) to cell wall components and secreted enzymes and metabolites. Lastly, we demonstrate that these tailored SWCNT sensors can also be transferred to purified nanotube building blocks, which enables a predictable design concept for sensor properties (emission wavelength and target specificity).