What researchers say

I used PhaseLab Instrument's IPSO SPR system during my final-year internship for my MTE engineering degree and Nano-Photonics Master's (dual degree). The main goal was to detect mercury in real time, using DNA aptamers, in increasingly complex aqueous media. Using the sensorgrams, the IPSO made it possible to visualize in real time phenomena such as the functionalization of the gold surface with DNA aptamers, and the interaction between the aptamers and mercury (association and dissociation). Analysis of the angular scans — specifically the shift of the amplitude minimum as a function of mercury concentration — also revealed a Langmuir isotherm and allowed us to determine the concentration at which the DNA strand folded.

Translated from French.

As part of these trials, I used the IPSO to evaluate the ability of a compact SPR sensor to measure the anti-SARS-CoV-2 serological response of blood serum samples provided by the Institut Pasteur. The main goal of this first series of measurements was to assess detection sensitivity under near-real conditions, and to extract the k_on and k_off kinetic constants.

I functionalized gold SPR chips using PEG chemistry to immobilize the SARS-CoV-2 Spike protein. The serum samples were then injected via microfluidics, requiring only a few tens of microliters per assay. Four patients were tested, with variable responses: some strongly positive, others weaker, and some negative.

The value of the IPSO was its ability to follow the sensorgrams in both amplitude and phase in real time, from surface preparation through to the interaction between the Spike protein and the IgG antibodies present in the sera. Unlike lateral-flow tests, which are essentially binary, the SPR measurement provided more quantitative information on the intensity of the serological response — not just the presence of antibodies, but their apparent ability to bind the immobilized Spike protein, directly, sensitively, label-free, and with small sample volumes.

Translated from French.

Master internship — detection of the GFLV virus, responsible for grapevine leaf curl.

The IPSO LAB is based on SPR technology, and despite my lack of knowledge in this field and no previous experience with the instrument, I was nevertheless able to put it to use very quickly, demonstrating just how easy it is to use. This feature allows people like me, with no experience in this field, to quickly grasp its functionalities and devote themselves to exploring the biological aspects of our subject of study.

I used the IPSO during my Nano-Photonics Master's internship, which aimed to develop an ultra-sensitive biosensor based on LSPR technology. My project required studying the adsorption kinetics of polyelectrolytes (PDDA and PSS) on gold, as well as determining the refractive index of these nanometer-thick layers. The IPSO is an ultra-sensitive instrument — it detects substances at very low concentrations — based on surface plasmon resonance. The software interface allows real-time monitoring of adsorption and of the refractive index changes in the medium. Getting up to speed only took a few hours of training: the instrument is compact and intuitive to use.

Translated from French.