MON-coated QCM sensors for the detection of bacteriophage-displaying peptides. Over the past decade, various quartz crystal microbalance (QCM) based biosensors have been developed that offer high sensitivity and short detection times. natural or synthetic biomolecular recognition components such as antibodies or molecularly-imprinted polymers (MIPs) coated on a QCM surface. Natural receptors suffer from instability while technical issues associated with MIPs lead to sub-optimal detection limits. We hypothesized that 2D-MONs might offer an alternative biomolecular recognition platform because they constitute a highly stable periodic array of active sites and can be easily processed to form thin films. Examples of 3D-MOF based QCM sensors for vapor/gas detection have been reported but such coatings are relatively thick (~ 1 µm). A 2D-MON based QCM sensor has been produced for ammonia detection but as far as we are aware there have been no other studies involving MON-based QCM sensors. QCM was used to assess intrinsic structural changes within MON-based water filtration membranes but not utilized as a sensor. Xie et al. designed a covalent-organic framework nanosheet-based QCM sensor to detect miRNA but in this case the nanosheet was simply employed to enhance signal generation in a complex probe DNA system. One major advantage of a QCM sensor is its sensitivity: detectable changes in adsorbed mass are of the order of one nanogram per cm 2 . The simplest model relating ∆f to m is the Sauerbrey equation, which is used to calculate the mass of the adsorbate.